You could put the YAML file in a secure cloud storage location. I’m using python 3 and AWS S3. If you are using “config” as the variable for the streamlit-authenticator configuration, then here’s a snippet that may help.
import yaml
yaml_data = yaml.dump(config, default_flow_style=False)
s3 = boto3.client('s3', aws_access_key_id=aws_access_key_id, aws_secret_access_key=aws_secret_access_key, region_name = region)
s3.put_object(Bucket=user_config_bucket, Key=user_config_key, Body=yaml_data)