You have that extra space in there. While HTML may not care, it is unusual and the test doesn’t like it. The test can’t account for every accountable variation, it expects standard formatting.
Next, the error message:
Your link element should be a self-closing element.
At various points of HTML history the rules for self-closing tags have changed. Sometimes there was a requirement for a slash (/) before the final angle bracket (’>’) and sometimes it is forbidden. In HTML5 it is optional. For whatever reason, the test is requiring it.
If I fix those two things, the code passes for me.