Two ways...
1. You've got obviously Instagram DM. So you've got the ability to just direct message that influencer on whatever platform you're trying to connect with them. I assume it may be Facebook or Instagram. So, send them a DM...
Hey, thinking of collaborating with you with our great new product. I've looked at your feed. I think it really resonates with our brand. Love your messaging, love your content. Would you accept £xxx for one post?
2. You can contact them via email.
Whichever one they reply to the quickest.
Answered by: Reece Douglas