After you've discovered which influencers you would like to be a part of your campaign, the next step is to activate them. When you activate a user, they are added to the campaign's workflow and will then be required to complete various steps before they can start contributing content.
To activate a users, select a list you would like to pick influencers from. Start by selecting multiple influencers, all of which will receive the same amount of compensation, click into "Activate Creators". This will bring you into a prompt that will ask for "Set Payment Amount" select this option and enter the compensation amount in the drop down field. Finally, select "Activate" and these influencers will appear in your manage board for your campaign.
Finally, click on in the Campaigns sub-menu to see your recently-activated influencers: