At present (March 2021) foreigners are still free to travel to most places of interest in Garze Prefecture including Daocheng Yading, Kangding, Tagong, Danba, Litang, Ganzi, Minya Konka, etc. 

To travel to these places a foreigner needs:

01. national tracking code
02. local health code
03. RNA test within 14 days (some places have loosen this and made this not obligatory)
04. resident proof or any formal document that can proof you are in China for at least 3 months (can be entry stamp on your passport, or your working visa with entry date, or resident card with dates)

The require on RNA test varies at different times. Although different places apply these regulations to different levels, for example hotels in Yading and Kangding will require foreign guests to have RNA test. And in Hailuogou Park they say an RNA test is required but their check is loose but in Yading Park they check every details of your test.

Airport in Chengdu, Kangding and Daocheng check your RNA test as well. So better to have it if you are going to use flight. Bus station the same, small bus stations such as Yading or Daocheng Bus Station they don't see foreigners often so they tend to ask all possible proofs you have or simply declining you using a bus. So if you have all the proofs it makes things easier and smoothier.

Hotels Available for Foreigners
In Kangding it is already back to normal. All hotels that could take foreigners can take foreigners but with the above proofs of course. In Tagong and Danba it is the same. In Daocheng the hotels are only starting to take foreigners by now so they may not be sure by themselves when you ask them. Although limited in numbers there are still hotels available for foreigners in both Daocheng and Yading.

Traveling in Chengdu and its sorroundings will require just a local tianfu health code and no rna test is required. The places requrie only a tianfu health green code include: chengdu and its suburban (dujiangyan, qingchengshan), Emei and Leshan.

The whole Aba prefecture including Siguniang and Jiuzhaigou are closed to foreigners.