How to set up distance calculation (and maps) on web site

Hi, we have a php web app using Google Maps in the moment where you can check for the nearest shop from your location. Then the 10 nearest shops with driving time are offered. The area which has to be covered is about 100 x 400 km, there are about 100 users per day doing this request (so 1000 times a distance maxtrix has to be called).

I am just getting started with OSRM, so I have very basic questions:

• Do I have to - or would it be better - to set up the map on our own (shared) server?
• What capacity would I need for our task?
• If yes, is there a way to do this just using php? I only came across this https://datawookie.netlify.com/blog/2017/09/building-a-local-osrm-instance/ which needs access on Linux, which we don't have in the moment. I found an api on githup, but that seems untouched for many years.

So any basic tutorial on how to achieve the task would be very helpful!