Hi @LiuTianyou 
, welcome to the forums! We are so glad you’re here. 
Have you taken a look at these two articles that detail how to link your repository? One via API and one is via the CLI. Give those a read and let me know if that helps.
If not, can you please share what steps you have taken to troubleshoot so I can assist you better and screenshots! That would help as well. Happy building! (: 