Well, the only strange thing I see is the HTLM extension (did you mean HTML or is it on purpose a different extension?). Then, I would rather use HT* instead of HT?, to catch both HTM and HTML.
But if you do it exactly as written… HTLM in the box, loading the “infected” eicar.htlm should trigger the alarm.
If you scan the file from avast window (thorough scan) - does it detect it?

Maybe one thought: since htlm is unknown to Notepad… isn’t it htlm.txt in fact (and .txt not showing)?