How do I start a loyalty programme for my restaurant?

Open Marketing, then Loyalty and stamps. Pick how a stamp is earned, how many stamps make a reward, and what the reward is. Tick Loyalty program active and press Save. That is the whole setup, and it takes about two minutes. Most restaurants do best with one stamp per completed order and a small goal, such as buy five get one free. The docs tab Loyalty and rewards has a step by step guide.