Put the link in your bio.. DMs are intrusive and lead to bans as people don't like spam messages... it's the same as spam email.. you'll have some that don't mind it and more that dislike it, you'll get more traffic with a bio link and a call to action in your bio, as well as on your posts. This applys for any niche.
I don't send messages thru DMs, the traffic is smaller and leads to account bans to quickly. As I just mentioned I use the bio, with a call to action in the bio as well as my posts. I also use domains for my links. You can use free websites, but the link won't last as long, especially if you're trying adult. Good luck.