Confluence supports Guest User access however, Forge currently does not support this functionality, so the app is not displayed for these users. Instead, the following message is shown:
Confluence spaces can be shared with individuals who are not logged into Confluence (anonymous users). Forge apps will not be displayed.
A feature similar to what JSM modules offer is needed. Refer to Access to Forge apps for unlicensed Jira Service Management users
This should work. Point blank. And 6 month later nobody even assigned to it. Then wonder the hesitate by some to adopt Forge.
We all hate getting 'bug' reports and having to tell them our app does work in a logical way due to Atlassian not making an effort to support paid users.