convert base64 string to image on SwiftUI

If I understand you correctly, you want to convert a base64 String to a SwiftUI Image.

/// I don't have your base64-encoded String, so I'll make a dummy one...
let sourceData = Data()
let base64String = sourceData.base64EncodedString()

/// Convert base64-encoded String to UIImage
guard let stringData = Data(base64Encoded: base64String),
      let uiImage = UIImage(data: stringData) else {
          print("Error: couldn't create UIImage")
          return
      }
/// Convert UIImage to SwiftUI Image
let swiftUIImage = Image(uiImage: uiImage)

Is that what you wanted to know?