Flutter Developer for Android [Bug Fixing & Release]

I am facing some errors in my existing Flutter project. It is a wallpaper app (due to older version of libraries mostly) & need some help with resolving those as it is not building, getting the auto wallpaper changing feature & play purchase working again. And finally pushing update on Play Store (We already have this app on Playstore but temporarily down due to policies so you need to abide by those too)

NOTE: MY BUDGET IS INR 5000 so only bid if you are comfortable.