ik know it had something to do with the iboutlet collectionView but i cant figure it out can sombody please help

 @IBOutlet var collectionView: UICollectionView!

        let headerId = "headerId"
        let arrImages = ["image1", "test"]
        let categoryHeaderId = "categoryHeaderId"

    override func viewDidLoad() {
           super.viewDidLoad()

           self.navigationItem.title = "The Closet"
           view.backgroundColor = .red
           collectionView.register(brandCollectionViewCell.self, forCellWithReuseIdentifier: brandCollectionViewCell.reuseIdentifer)
           collectionView.register(brandCollectionReusableView.self, forSupplementaryViewOfKind: categoryHeaderId, withReuseIdentifier: headerId)

           collectionView.collectionViewLayout = createCompositionalLayout()

           collectionView.reloadData()
       }

       //MARK: - Helper Method
       private func createCompositionalLayout() -> UICollectionViewCompositionalLayout {

           return UICollectionViewCompositionalLayout { (sectionNumber, env) -> NSCollectionLayoutSection? in

               switch sectionNumber {

               case 0: return self.firstLayoutSection()
               case 1: return self.secondLayoutSection()
               default: return self.thirdLayoutSection()
               //case 2: return self.thirdLayoutSection()
               //default: return self.fourthLayoutSection()
               }
           }
       }

       private func firstLayoutSection() -> NSCollectionLayoutSection {

           let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1), heightDimension: .fractionalHeight(1))

           let item = NSCollectionLayoutItem(layoutSize: itemSize)
           item.contentInsets.bottom = 15

           let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(0.9), heightDimension: .fractionalWidth(0.5))

           let group = NSCollectionLayoutGroup.horizontal(layoutSize: groupSize, subitems: [item])
           group.contentInsets = .init(top: 0, leading: 15, bottom: 0, trailing: 2)

           let section = NSCollectionLayoutSection(group: group)

           section.orthogonalScrollingBehavior = .groupPaging

           return section
       }

       private func secondLayoutSection() -> NSCollectionLayoutSection {

           let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(0.33), heightDimension: .absolute(100))

           let item = NSCollectionLayoutItem(layoutSize: itemSize)
           item.contentInsets = .init(top: 0, leading: 0, bottom: 15, trailing: 15)

           let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1), heightDimension: .estimated(500))

           let group = NSCollectionLayoutGroup.horizontal(layoutSize: groupSize, subitems: [item])

           let section = NSCollectionLayoutSection(group: group)
           section.contentInsets.leading = 15

           section.boundarySupplementaryItems = [
               NSCollectionLayoutBoundarySupplementaryItem(layoutSize: .init(widthDimension: .fractionalWidth(1), heightDimension: .estimated(44)), elementKind: categoryHeaderId, alignment: .top)
           ]

           return section
       }

       private func thirdLayoutSection() -> NSCollectionLayoutSection {

           let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1), heightDimension: .fractionalHeight(1))

           let item = NSCollectionLayoutItem(layoutSize: itemSize)
           item.contentInsets.bottom = 15

           let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(0.8), heightDimension: .fractionalWidth(0.35))

           let group = NSCollectionLayoutGroup.horizontal(layoutSize: groupSize, subitems: [item])
           group.contentInsets = .init(top: 0, leading: 15, bottom: 0, trailing: 2)

           let section = NSCollectionLayoutSection(group: group)

           section.orthogonalScrollingBehavior = .continuous

           return section
       }

       private func fourthLayoutSection() -> NSCollectionLayoutSection {

           let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(0.5), heightDimension: .fractionalWidth(0.5))

           let item = NSCollectionLayoutItem(layoutSize: itemSize)
           item.contentInsets = .init(top: 0, leading: 0, bottom: 15, trailing: 15)

           let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1), heightDimension: .estimated(500))

           let group = NSCollectionLayoutGroup.horizontal(layoutSize: groupSize, subitems: [item])
           group.contentInsets.leading = 15

           let section = NSCollectionLayoutSection(group: group)

           return section
       }
   }

   //MARK: - UICollectionViewDataSource Methods
   extension brandViewController: UICollectionViewDataSource {

       func numberOfSections(in collectionView: UICollectionView) -> Int {

           return 1
       }

       func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {

           switch section {

               case 0:
                   return 3
               case 1:
                   return 1
               default:
                   return 1
           }
       }

       func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

           let cell = collectionView.dequeueReusableCell(withReuseIdentifier: brandCollectionViewCell.reuseIdentifer, for: indexPath) as! brandCollectionViewCell

        if let name = arrImages.randomElement() {

                    cell.configure(withImageName: name)
                }
           return cell
       }

       func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {

           let header = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: headerId, for: indexPath)

           return header
       }
   }

Is your collectionView actually connected to the storyboard?