Drupal::service('renderer')->renderPlain is deprecated since 10.3.0

sarwan_verma → made their first commit to this issue’s fork.

I have reviewed MR !18 and encountered some issues, which I have now resolved and pushed the
changes. Thanks!

This needs to be postponed until 10.3 is required.

There's no point in using the deprecation helper in one place but have two other changes that break on 10.2