Allow issue fields (addon's predefined custom fields) for next-gen

Hi team,

We are updating our addon to support next-gen projects. Something I could not find is how Issue (addon) fields are supported.

https://developer.atlassian.com/cloud/jira/platform/modules/issue-field/ 2

How can a project admin add one of our addon fields to an issue type in next-gen projects? We would need to fall back to custom fields with manual user configuration.

Cheers
Fernando