What are the specific steps to transfer from Hong Kong to Beijing and Taipei? I have a Hong Kong and Macao certificate and two endorsements to Taiwan.

At Beijing airport, check in with Hong Kong and Macao Pass and valid Hong Kong endorsement and fly to Hong Kong.

When you arrive at Hongkong Airport, you can apply for a boarding pass to Taiwan Province with your passport and entry permit.

Then when you want to go to the boarding gate, you have to go out of Hong Kong Customs first. At this time, you can go out with the Hong Kong and Macao Pass. As soon as you enter and leave the country, your Hong Kong endorsement will be used up. When waiting for the plane, you can show your passport and entry permit.

When you come back, when you arrive at the Hong Kong airport, you can use your passport to enter the Hong Kong airport, then check in and fly to Beijing.