Wolverhamption is called Wolverhampton Business Airport
AFAIK...not international.....
TWR *is* an ATC service - unless the post is incorrect. Because the callsign for the a/d would be radio or information NOT...xx TWR.
It obviously wasnt an AFIS...because in either case they do not control *anything* airborne (or in the case of radio - anything at all).
Given there was an instructor on board we can safely assume a clearance to land was necessary...