Launched a roommate matching app 5 days ago. I have users, but 0 available rooms. How do I solve this cold start? "i will not promote"

Hey everyone, I need tactical advice on a chicken-and-egg problem. I just launched Coloca, a roommate matching platform for young adults and students in my city. We went live 5 days ago. (you gotta know first there's nothing like that where i live) The Problem: I’m getting organic signups, but 100% of them are looking for a room. Absolutely nobody is posting an empty room to split rent. Room seekers are logging into an empty platform. Current Constraints: Zero ad budget (relying on Reddit, local Facebook groups, and WhatsApp). I am strictly targeting existing renters looking to split rent. I am not dealing with landlords right now. My Ask: For those who have built a two-sided marketplace: 1. What "unscalable" things did you do to seed your first 10-20 listings manually? 2. Should I scrape local Facebook groups, DM the posters, and offer to create their listing for them? 3. How do you convince someone who already has a room to take the time to post on a brand-new, unproven app, especially as i said there's nothing like it before so probably most of the users here are not used to this kind of stuff? Any harsh truths or growth hacks are appreciated!