PT is indicated as treatment for AS. I believe that activity is huge, probably the most important thing for improved life with AS.
From personal experience, the AS exercises done in PT are very similar to the ones I find super helpful in yoga. i can relate to not going to a PT that isn't familiar with AS not being worth my time.
SAA has several resources on AS & PT . My favorites are seminar presentations. some of these are done by PTs that have AS and by PTs that work out of a spondylitis clinic and have tons of experience with people with AS. check out PTs Sturdy, Lui, and Angelo.
https://youtu.be/cOp2q-L927U https://youtu.be/TWSHUmMhluU https://youtu.be/m2q5u-Gz5UUhttps://spondylitis.org/resources-support/educational-materials-resources/seminars-webinars/ Also SAA has exercise poster that lists the PT exercises that are often done specifically for AS.
SAA also streams exercises taught by PTs (and one is taught by yoga therapist).
https://spondylitis.org/resources-support/educational-materials-resources/back-in-action-again/ Hope this helps.