Platform connections
Paste the keys each network gives you in its developer settings. Once a network has approved posting for your account, switch on automatic posting and your scheduled posts will go out at the time you set.
Keys are kept on this computer only, in this browser. They are never shown in the posts or included in your downloads. Clear them any time by emptying the boxes and saving.
Publishing starts working for a network as soon as it approves posting for your account.