front-end mobile app android and ios to integrate with existing backend (React-Native or Flutter)

We need to build the mobile app front-end and integrate it with an existing backend through API integration. The app must support multilanguage. We will provide the UX and all the documentation regarding the mapping between the wireframe/UI and the APIs including the postman APIs collection.
In attached you can find the wireframe and the api mapping document (the UX will be provide to selected candidate).
The work will be consider completed once the apps are pushed and public on the play and apple store, and the source code is completely pushed on the company git account.
Based on previous experiences we only want to commit the project on 1 milestone. It means that we will pay the complete work once received the complete project.
The project budget is 2000 Euro and could be negotiate but within a limit percentage (max 25% ).
Please, avoid to contact if your offer cannot be withing the above points.