revert minify enabled and progaurd efect on decompiled apk

I have developed an application before and Now I can't find my application source code.
I want to make some changes to my application.

Now I just have my keystore(jks file) which I have use it to sign my application before.
I use online Apk Decompiler to decompile my application but It does not give my desired result. I need it to edit my codes and give it to the customer but It gives me code preview like below with Incomprehensible class and method names.

My decompiled APK folders directory

My Code Preview

I know that this problem is for setting minify enabled to true for release mode in gradle .

Is there any way to revert decompiled code to understandable code or revert it with keystore or decompile application apk file with understandable source code?

I really need to decompile this apk and do some changes on it . Specially application source files.

Any help will be appreciated :)

from revert minify enabled and progaurd efect on decompiled apk