Live selling, invoicing to pay off site?

I cant find my answer in a search because everything comes up as selling live with tiktok shop. What I want to know is- is it ok to sell live and invoice a buyer directly? I see people showing items, and you post claim in chat to "purchase" it and then you need to message the seller and they invoice your email. Im guessing paypal, venmo or whatever. But is this ok by tiktok rules? I thought it wasn't. Im about to do my first live and I wont be selling this time but Im interested in doing this as I have a lot of vintage items and I can do grab bags of things like stickers and pther handmade stuff I sell .