Go to My Influencers and click on Add Influencer to fill out their profile and connect their social media channels. If you don't know the logins you can send their Post For Rent profile and they will connect them.
You'll need to choose if you will be the only one managing their profile or you give them access so they will be able to get in touch with the advertisers.
To make sure you'll always get your cut, you can set it based on your agreement with your influencers and receive the money with the exact percentage of share automatically, to your bank account or to your PayPal.
You can register your influencers to your portfolio for 20$/Influencer/Month.