Flutter developer wanted for adjusting existing Delivery Flutter Mobile App project.

We need a Flutter developer for our Delivery App. The app is written in Flutter for compiling for Android, iOS or Web. We use Android Studio to code. UI templates have to be merged in the functional source code and screenflow according to the numbered jpg's, we have source code for the new screenshot's. You have to adjust the buttons functionality as well as the corperate identity design of the whole App. The project is hosted in Subversion revision control environment. We need help for compiling in iOS Xcode.