REST API for cloud addon application to allow third parties integrate with addon data

Hi,
We have a Jira cloud addon and we want to have a REST api for clients who want to integrate their internal apps with data from our addon. Authentication is the issue, since we use JWT authentication, third parties cannot directly call our APIs directly.
Is there solution to this? If anyone has already done this, can you please give us some pointers to start with?
Thank you,