I clicked on mspath's link out of interest's sake. It seems quite simple: if you go to "choose your camino" on the right side of the screen, and put your destination as Pasajes de San Juan, they give you a list of all the accommodation they deliver to (Pasai/Pasajes is the same place in Basque/Spanish)
[Edit: oops! Had a niggling doubt so went back to check and it seems the accommodation options apply to the collection point and not delivery point! I tried Pasajes de San Juan as a collection point to see if there were accommodation recommendations, but nothing comes up which is really weird. But Pasajes is definitely on their route, and they give you the option to "pay and choose your accommodation later" so it seems they're quite flexible. In fact, in the FAQs, they say that they will recommend a location or "friendly place" close to your accommodation if it's is not on their list. So shouldn't be a problem, but probably best to write to them anyway).