For auto-checkout, if you select "N/A" as your profile, you will have the ability to select the profile to use for checkout once the task has passed the waiting room. If you select an actual profile, it will automatically use that profile and not allow you to select a profile once passed the waiting room.
Once you pass the waiting room, the status will change to Click to ACO (see example below).
The next option will be to select your Auto-Checkout profile. Use the drop-down to select your profile for auto-check. Select Start Auto-Checkout.
The Status will change to Submitting Delivery -> Getting Shipping -> Generating cookie -> Submitting Shipping -> Submitting Payment -> Processing -> Check your Email.