The Earnings Program Terms are at /legal/earnings-program. On My earnings → Getting paid → Accept the program terms, read the key points, type your full name as your signature, and accept. The person accepting confirms they may bind the business.
Your earnings build up before you accept; you only need to accept before your first payout.
New versions. If the terms change, you get at least 30 days' notice, and your dashboard asks you to accept the new version before your next payout. What you earned before a change is never reduced by it.
The terms add to our Terms of Service (/legal/terms); where they differ about the program, the program terms apply.
Your My earnings page shows every payment that earned, what is clearing and what you can be paid. Reply to any program e-mail and a person will look into anything that looks wrong.