@kaveman I don't know if proton vpn works for your phone as i don't know (see) the name of your phone but proton vpn works on every smartphone i use(d) : OPO, BQ E5 HD, BQ 4.5, NEXUS 5, the tablet BQ M10 and my daily driver Volla phone currently.
Read carefully and apply the procedure of this thread and it should work unless there is something that makes your smartphone incompatible.

@kaveman Good stuff, you should be there by the time this is posted.