You may wish to look at `roles/custom/matrix-bridge-mautrix-instagram/templates/config.yaml.j2` and `roles/custom/matrix-bridge-mautrix-instagram/defaults/main.yml` to find other things you would like to configure.
You then need to start a chat with `@instagrambot:YOUR_DOMAIN` (where `YOUR_DOMAIN` is your base domain, not the `matrix.` domain).
Send `login YOUR_INSTAGRAM_EMAIL_ADDRESS YOUR_INSTAGRAM_PASSWORD` to the bridge bot to enable bridging for your instagram/Messenger account.
You can learn more here about authentication from the bridge's [official documentation on Authentication](https://docs.mau.fi/bridges/python/instagram/authentication.html).