I've got drop foot in both feet and require ankle-foot orthotics to walk. Without them (primarily in bathrooms and showers), it's a struggle.
On the Frances in 2017 (from SJPP) and the Portuguese in 2019 (from Porto) there were very few showers and baths equipped for disabled access outside the larger cities in the places I happened to stay. I took
a plastic grip handle that affixes to smooth shower walls, and it came in handy. There are also a lot of places that have no shower hooks or benches to change on.
Where there were facilities for the disabled, I passed the "eye test" and did not require any documentation.
This amounted to using a shower/toilet combo that was mostly out of use as a shower, or requesting a bottom bunk.
Many albergues have all their sleeping facilities upstairs, so being able to climb stairs is a requirement.
Alone among my Camino friends, I was grilled in the Compostela office about whether I had used motor vehicle transportation to complete the Camino in 2017 (again, probably because of the "eye test"), which I consider a second badge of honor with that Compostela!