When I'm logged into https://bugs.funtoo.org , these queries work fine :

https://bugs.funtoo.org/rest/api/latest/search?jql=issue+in+watchedIssues%28%29&validateQuery=True&startAt=0&maxResults=-1

https://bugs.funtoo.org/rest/api/latest/search?jql=watcher=palo&validateQuery=True&startAt=0&maxResults=-1

But they don't work when I'm logged out.
I can't use the Basic authentication like it is described here :
https://developer.atlassian.com/cloud/jira/platform/jira-rest-api-basic-authentication/

To use bugwarrior it seems I need exactly this type of authentication to import everything I watch into taskwarrior

I hope this is just a checkbox that has to be clicked somewhere in the configuration jungle of jira.