Mostly 45-rule work.
1. 45 rule on N1 -> R4C2 - R1C3 = 8 -> R4C2 = 9, R1C3 = 1. 45 rule on N4 -> R6C1 = 8. 45 rule on N7 -> R789C3 = 23 = {689} -> R9C34 = [61], R78C3 = {89}, R78C4 = {37|46}, R1C1 = 9.
2. 45 rule on C4 -> R6C4 - R5C5 = 8 -> R5C5 = 1, R6C4 = 9, R4C1 = 1, R6C7 = 1, R8C8 = 1, R9C89 = {89}, R78C6 = {59}. 45 rule on N789 -> R6C5 = 5.
3. Mop-up. 45 rule on R9 -> R8C12 = 6 = {24}, R9C12 = {35}. 45 rule on N9 -> R9C7 = 4, R78C9 = {57}, remaining cells of 12(4) cage = {236}, R9C56 = {27}, R78C4 = [46], R8C7 = 3, R7C12 = [71], R78C9 = [57], R78C5 = [38], R78C3 = [89], R78C6 = [95]. 45 rule on N236 -> R45C7 = 10 = {28}, R7C78 = [62]. 45 rule on N6 -> R4C89 = 8 = [53], R23C9 = {18}, R9C89 = [89], R5C8 = 9, R6C8 = 7, R1C9 = 2, R3C78 = [93]. 45 rule on R4 -> R4C34 = 11 = [47], R5C4 = 3, R5C12 = {25}, R45C7 = [28], R4C56 = [68], R56C6 = [42], and you carry on....