Android pem cert inside keystore

Question

I have project not made by me but right now I need to fix some things, Someone added an pem certificate (private key and certificate) inside a project which allows app to communicate with server (used inside network_security_config trust anchor), the problem is that I need to build signed release apk, build process is crashing because pem cert is inside a project which is obvious rule violation, how can I add this pem cert inside a keystore(or create new one) or is there any other solution for this problem? Maybe the way of communication is bad. Thank you for any answers!

I tried to create new keystore with cert inside but no success