Reproducible by going to the app (generic error appears)

https://marketplace.atlassian.com/apps/1219292/team-worklog-reports?tab=support&hosting=cloud

The error message tells customers to contact Atlassian support:
 

Something's gone wrong
Our team has been notified. If the problem persists, please contact Atlassian Support.
Reload page

However, since Team Worklog Reports is a third-party app that functions outside of standard Jira Cloud functionality, we recommend reaching out to marketplace vendor Gebsun directly through their support channel here:

• Gebsun support
• support@gebsun.com