I ran a game online for a few months, and my most successful way to recruit by far was OSR Discord servers. I think this is the one I had the best luck in: discord.gg/6vqF25E
There’s one more OSR Discord I know of, and I don’t know that they have a public LFG section, but there are some games run on the server that people seem able to join. If you’d rather run one, maybe they’d be open to you running something there. I’m not familiar with this one, so you’ll have to check it out yourself. discord.gg/B6wU8TPTEa