@Frank *******
It can be done online. If the form is submitted by you, rather than by house owner, you need info from them though, like owner account info etc. On some ABnb listings now, the “host” says upfront they will give “guest” the necessary info but it’s up to “guest” to file the TM30. Ask your GF’s landlord if he is going to file it. It’s my understanding as well that if the house owner doesn’t file it within 3 days, whoever does eventually file it will pay a fine. You or the landlord; whoever files it, will pay the fine. I don’t recall how much the fine is. Good luck; I hope your landlord is on top of things and cooperative. You will either need a hard copy of the form to give to immigration or proof that the form was done online. My visa agent handled all that since I had no TM30.