DM them a straightforward message, and ask an influencer something like: “Hi Johnny, I would like to pay you for promoting my ____ product. Is that ok, and what would be your fee?”
That’s right, that’s right: The whole notion of “outreach” to Influencers is a myth. There is no outreach, there is “hiring.” If you want to work with an Influencer who is a professional and will take your product and business seriously, think “hiring” instead of “outreach.” Think simple, talk in short sentences, and get to the point. What you want to know is:
1. Will he/she/it do it.
2. How much.