Good morning! I assume we're talking post-COVID/long COVID care here?
I know of one primary care guide from the BMJ that hits on this off the top of my head that'll give you a good start with references to follow:
https://www.bmj.com/content/381/bmj-2023-074937
Anecdotally, this comes up fairly frequently in the long COVID groups that I keep an eye on and a name that people bring up from time to time is Patrick McKeown. If you search through YouTube(or whatever YouTube alternative you use) for his name you'll hit on some videos that some people say have been very helpful to them.