(1) If you account is a free account, then you just need to log in to www.cameraftp.com, then click your username on the top-right corner to go to Account page. Then click Subscribe. You will see 4 recording types: Image recording plans, video recording plans, timelapse recording plans and local recording plans. Select a recording type, then select a plan, or customize a plan to order. Please watch this video for more detailed information about CameraFTP service plans and pricing:
https://youtu.be/rujJhcoumBY
(2) If you want to add a camera license, then you can simply order a new plan. The new plan will be added to your current service plans.
(3) If you want to change your service plan, you can order a new plan first; then go to My Cameras page, click the Settings icon below your camera thumbnail. You can then bind the camera with the newly ordered camera license. After that, go to Account page, click Manage Subscriptions, you can then cancel the old subscription plan.