Can I get a 1 year apartment lease on the DTV? I Just got approved. Thank you

Is it absolutely necessary to show an apartment lease for retirement visa renewal or is a TM30 enough? Can I just say I'm living with my gf (the lease is in her name). I originally got my retirement visa in Bangkok Div 1 if that matters. They sent someone to come inspect my apartment to make sure I'm actually living there.

If an apartment lease is required, what's the minimum length. Is a 3 month lease adequate?

The time to renew my STV is approaching, I'm staying in an apartment with a rolling monthly contract. I understand prepayment for duration is a requirement, have immigration shown any flexibility around the requirement or is it strictly enforced.