Went to train a LoRA and this option wasn't here yesterday. As a non-subscriber I can't tell you anything more. Feel free to tell us the details in the comments if you are (cost is a big one worth noting).
The tooltip says this is "Currently" limited to subscribers, implying this will eventually be open to every user (at least those with what I'm sure will be a hefty amount of buzz), but who knows how long that will take (I think the option on the trainer to train alternate types of LoRA, presumably stuff like DoRA, has been there for literal years at this point and inactive).
Edit: As of at least April 25th, this is now open to everyone instead of subscribers only. Changed title to reflect that.