Note: Even though you’re testing on staging, you need to use production URLs, like those listed below. Anything with the test subdomain will error.
Navigate straight to https://test.archiveofourown.org/abuse_reports/new
Fill out the form manually
Enter one of the following variant URLs manually in the field:
Look at the lovely "Url does not appear to be on this site." error for a URL that would normally redirect to the site correctly
You should not get an error message. The report should be submitted successfully.