Find Master Mao at Wanmintang in Liyue Port to complete the dialogue, enter the restaurant and choose a three-silk menu to buy. The method is as follows:

Tools/materials: iPhone 13, iOS 15.3, Protogod 2.5.0.

1. Find Master Mao of Hong Kong People's Hall and complete the transaction. Click "I want to pack and go" on the right.

2. After the restaurant is opened, turn up the goods in the restaurant, find the formula of three threads, and select it. After selecting it, click Buy in the lower right corner.

3. In the pop-up confirmation box, click the Buy button below, and you will get the formula of three threads after purchase.