The only way I know is to use a browser to go to Nostrnest.com and create a space and then copy the link and send it to who you want to join. It will be open for the public to see it. Sometimes there are no nests (spaces) but I have a feeling that's going to start to change soon

I think those things are scams probably. Those airdrop posts. Just a feeling

My bad.... Nostrnests.com

Here. I started a nest https://nostrnests.com/zpc790