I was building my app and not using any ad component not existing or any ad extension but still I am getting ad subscription not found problem.
List all the extensions you are currently using.
Sorry it was my fault.
In recent months I used Niotron primium and by mistake added unity banner component in HVarangment which was invisible, yesterday I try to build apk without finding it and its gives me that error.
Sorry for trouble, and thank you @JEWEL for replying.
Satwik