We loved our stay at Elena & Donato's charming apartment as per the title. Elena was there to greet us on check in and explained everything in detail before leaving us to our own privacy for the rest of the trip. They were also contactable on WhatsApp or the airbnb app during the duration of the stay. Communication was also great from the start of the booking process till check out.
As described, there is a lift available in the building but you'll have to bring your luggage up a flight of stairs to your own space with the private terrace, living / dining / kitchen area, bedroom and bathroom. Everything you require is pretty much provided as per their description.
It is about 20 minute walk from the main train station and about 25 minute walk to the old town.
We thoroughly enjoyed our visit to San Sebastian and it was made more special by the excellent hospitality of Elena & Donato.