Update an old Android app

Hello, I’m trying to update an android app.

I’ve started with this app when it was Ionic 2 R.C.0 and a my-release-key.keystore was produced. Now, I made an update and tried to upload it to Google Play, but when I try to enter the

jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore my-release-key.jks app-release-unsigned.apk my-alias

command, It tells me that there is no .jks on my outputs/apk/release file.

When I change it to jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore my-release-key.KEYSTORE app-release-unsigned.apk my-alias, It throws me this error:

jarsigner: Certificate chain not found for: my-alias. my-alias must reference a valid KeyStore key entry containing a private key and corresponding public key certificate chain.

I don’t know if I should update nor how to do so.

Thanks for the time!