Flutter app custom fields for FluxStore app

Hello guys. What we want is that fields from website (see image) to appear on a fluxstore app. We have 2 fields already added but they were not working properly. Also IBAN field is missing from app. Basically what we want is same fields from website checkout (https://emve.ro/checkout/) to also appear on app(check app- https://emve.ro/qr-code-page/ )
If any questions please ask. Also we are searching for long term collaboration.