Use one of the two options of how to create a base64 password provided below:
Python3 interactive shell
from autoscaler.core.helpers import string_to_base64string
string_to_base64string("your-app-password-here")
Shell
echo -n $BITBUCKET_APP_PASSWORD | base64
or for oauth
id, secret
echo -n $BITBUCKET_OAUTH_CLIENT_ID | base64
echo -n $BITBUCKET_OAUTH_CLIENT_SECRET | base64