cxb6#
Mate in 1

Yes bxc6# is the winning move.
You can examine the board to prove that the Black last move was indeed b7-b5. Among the candidate moves:
Kb6-a7: impossible, the two kings would have been in contact.
Bc7-b8; b6-b5: impossible, the white king would have be in check with Black to move.
Kb6-a6: impossible, the black king would have been in a double check that is impossible to set up.
Thus the only previous move the Black played is b7-b5 allowing cxb6 e.p.#
Analyzing,
Dragon.Jade :-)
Hello, here I propose you a tentative quizz.
White moves and mate Black.
Do you have an idea?
Tentatively,
Dragon.Jade :-)