21.Qb1 Nb6->d8
22.Nd2
Qc7
wfb
22...Qc7
23.Rb3
Re7
c5
a5 Nc3 change to point at Rb3
23...Re7
24.a4 c5
The knight can change the direction they are facing any time they move. They can also spend a move standing still to change direction.
You can't move your pawn to a5 and change the direction of a knight on the same move.
Nd7 change direction to the bishop
Nxd5
25.a5 Nd7->d6
26.Nxd5
21.Qb1 Nb6->d8