Hi
pattipeep!
Download GPX, KML tracks from here::
https://www.santiago.nl/downloads/ option to translate from Dutch at top of webpage!
You need offline map app like Osmand (uses GPX) or Maps me (uses KML)or the like!
Download GPX track from the website to your computer send an email to yourself on phone/tablet with the GPX file as attachment !
Open the file in the email on your phone /tablet and you should be asked where you want to open it ,if you have the above two apps for example choose your favourite app!
Gpx viewer should open it in the map app OSMAND!
Or alternatively KML file for Maps me/Google Earth!
If it doesn't check the download manager!
Well that's what i did for my coastal i am no expert!
(In Osmand which is what i used (it has voice navigation for walking and lots of other choices like add direction arrows,avoid steps, shows street lighting, transport, accommodation ,cafes etc) download all Caminos in Portugal and in the navigation options FOLLOW TRACK it gives them all as individual tracks choose COASTAL!)
Hope this helps: others are more tech savvy than me
but you will defo get help.
Buen Camino
Woody