how to fix flutter and dart version, null-safety in android studio

The difference of the android studio version always gives me the problem of not being able to export the app’s file.apk.

For example: I am now facing the same problem with an application developed using flutter, but this time I could not solve the problem and I am looking for someone to help me.

Problem: My version differs from the version in which the application was developed. bytheway, I downloaded the flutter version that was used, but it does not fix the problem.
Note: I do not have experience in application development but I want to get rid of this problem in a systematic way. Thanks to all

enter image description here