Android Studio includes a tool to create a new key in the Generate Signed Bundle or APK wizard but here's how you can encode and decode your own key

Encoding

Step 1

openssl base64 < akadenia.jks | tr -d '\n' | tee akadenia.jks.base64.txt

Step 2

openssl enc -base64 -in key.jks -out signing_key.b64 | tr -d '\n' | tee basereactnative.jks.base64.txt

Decoding

openssl enc -d -base64 -in signing_key.b64 -out akadenia.jks