I had the same problem and solved it on Ubuntu by deleting the cache of QtCreator using :

rm -R ~/.cache/QtProject

I have the same problem

:-1: error: Cannot find application binary in build dir .../build-ICS_MedicalDemo-Android_Qt_5_15_13_Clang_Multi_Abi-Debug/android-build//libs/x86_64/libICS_MedicalDemo_x86_64.so. What could be the issue in this case ? I have already set ANDROID_ABI to correct x86_64 setting.