You can add Influencers by using the Upfluence Chrome Plugin:
Go to the influencer's social media platform.
Click on the Upfluence plugin on the top right of the window.
Click on "Move Influencer" to add the Influencer into a new/existing list.
If the influencer is not in the Upfluence database, you can add them directly by clicking "Add Influencer".
Use the following link to download the Upfluence Plugin: Chrome Store