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Uses the numbers 0-9, one of which is missing which is part of the puzzle.

Prelims

a) R1C67 = {69/78}
b) R23C3 = {49/58/67}
c) R34C1 = {79}
d) R45C2 = {49/58/67}
e) R67C7 = {79}
f) 7(3) cage at R1C1 = {016/025/034/124}
g) 7(3) cage at R1C4 = {016/025/034/124}
h) 7(3) cage at R2C6 = {016/025/034/124}
i) 7(3) cage at R2C8 = {016/025/034/124}
j) 4(3) cage at R5C5 = {013}
k) 7(3) cage at R5C7 = {016/025/034/124}
l) 7(3) cage at R6C1 = {016/025/034/124}
m) 7(3) cage at R6C2 = {016/025/034/124}
n) 7(3) cage at R7C8 = {016/025/034/124}
o) 7(3) cage at R8C3 = {016/025/034/124}
p) 7(3) cage at R9C5 = {016/025/034/124}

1a. Naked pair {79} in R34C1, locked for C1
1b. Naked pair {79} in R67C7, locked for C7, clean-up: no 6,8 in R1C6
1c. Naked triple {013} in 4(3) cage at R5C5, locked for N5
1d. 7(3) cage at R6C2 = {025/124} (cannot be {016/034} which clash with 4(3) cage), no 3,6, 2 locked for R6
1e. 3 of 4(3) cage must be in R6C56 (which cannot be {01} which clashes with 7(3) cage), 3 locked for R6
1f. Killer pair 0,1 in 7(3) cage and R6C56, locked for R6
1g. R6C1 = {456} -> no 4,5,6 in R7C12
1h. 7(3) cage at R5C7 = {025/034/124} (cannot be {016} which clashes with R5C5), no 6
1i. Killer pair 0,1 in R5C5 and 7(3) cage, locked for R5
[At this stage 0,1,2,3,7,9 are in all rows, columns and nonets.]

2a. 17(3) cage at R4C4 = {269/278/458/467}
2b. Hidden killer pair 7,9 in 17(3) cage and R5C4 must each contain one of 7,9 for N5 -> 17(3) cage = {269/278/467} (cannot be {458}), no 5, R5C4 = {79}
2c. Hidden killer pair 0,1 in R4C3 and 7(3) cage at R6C2 for N4, 7(3) cage (step 1d) contains one of 1,2 -> R4C3 = {01}
2d. R4C3 = {01} -> R5C34 = {79}/[89], 9 locked for R5, clean-up: no 4 in R4C2
2e. Killer triple 7,8,9 in R4C1, R45C2 and R5C3, locked for N4
[8 must also be used in all rows, columns and nonets since 7,8,9 are required for R4C1, R45C2 and R5C3.]
2f. 8 in C1 only in R89C1, locked for N7
2g. 17(3) cage at R7C4 = {089/269/278/359/368/458/467} (cannot be {179} which clashes with R7C7), no 1
2h. R6C789 = {789} (hidden triple in R6), locked for N6
2i. 8 in C7 only in R123C7, locked for N3
2j. R168C8 = {789} (hidden triple in C8)
2k. Naked pair {79} in R1C68, locked for R1

3a. R5C1 = 3 (hidden single in N4)
3b. 7(3) cage at R5C7 (step 1h) = {025/124}, 2 locked for R5 and N6
3c. 2 in R4 only in R4C456, locked for N5
3d. 7(3) cage at R6C2 (step 1d) = {025/124}
3e. R6C4 = {45} -> no 4,5 in R6C23

4a. If 6 is one of the numbers used then 6 in N6 only in R4C789, locked for R4 or if 6 is missing then no 6 in R4 -> either way no 6 in R4C2456, clean-up: no 7 in R5C2
4b. Cannot have all of 4,5,6 in N5
4c. 17(3) cage at R4C4 (step 2b) = {269/278/467}
4d. Consider placements for R6C4 = {45}
R6C4 = 4 => 17(3) cage = {269/278}
or R6C5 = 5 => 17(3) cage cannot contain both of 4,6
-> 17(3) cage = {269/278}, no 4, 2 locked for N5
4e. Naked pair {45} in R4C6 + R6C4 -> N5 cannot also contain 6 so 6 is the missing number, clean-up: no 7 in R23C3, no 7 in R4C2
4f. 17(3) cage = {278}, 7 locked for N5 -> R5C4 = 9

5a. If R23C3 and R45C2 both have the same combination then R89C1 must also have that combination but there’s no 9 in R89C1 -> at least one of R23C3 and R45C2 must be {58} -> CPE no 5,8 in R123C2
5b. R1C7 = 8 -> R1C6 = 7, R5C36 = [78], R4C3 = 1 (cage sum), R34C1 = [79], R4C2 = 8 (hidden single in N4) -> R5C2 = 5, R6C1 = 4, R6C4 = 5, R4C6 = 4
5c. 8 in N1 only in R23C3 = {58} -> R3C2 = 9 (hidden single in N1) -> R23C5 = [98] (hidden pair in N2), R23C3 = [85], R2C9 = 7 (hidden single in N3)

6a. Naked pair {02} in R6C23, 0 locked for R6 -> R5C5 = 0 (hidden single in N5)
6b. R4C6 = 4 -> R23C6 = {03/12}
6c. Killer pair 1,3 in R23C6 and R6C6, locked for C6
6d. R1C5 = 5 (hidden single in N2)
6e. 4 in N2 only in R123C4, locked for C4
6f. 7(3) cage at R2C8 = {025/034} (cannot be {124} which clashes with R5C8), no 1, 0 locked for C8
6g. 7(3) cage at R7C8 = {025/034} (cannot be {124} because naked triple {124} in R579C8 clashes with 7(3) cage at R2C8) -> R8C7 = 0, R79C8 = {25/34}
6h. R5C8 = 1 (hidden single in C8)
6i. 7(3) cage at R8C3 = {124} (only remaining combination), locked for R8, 1 locked for N8
6j. 7(3) cage at R1C4 contains 4 for N2 = {034} (cannot be {124} which clashes with R8C4), 0,3 locked for C4 and N2

7a. R89C1 = {58} (hidden pair in C1)
7b. 17(3) cage at R8C2 = {278/359} (cannot be {089} because R8C2 only contains 3,7, cannot be {179} because R9C1 only contains 5,8, cannot be {458} because 5,8 only in R9C1) -> R9C3 = {29}
7c. Variable hidden killer pair 7,8 in 17(3) cage at R7C4 and R9C4 for N8, R9C4 cannot contain more than one of 7,8 -> 17(3) cage (step 2g) = {458} (cannot be {089} because 0,9 only in R7C6, cannot be {278} which clashes with R9C4) = [845]
7d. Naked pair {12} in R8C45, 2 locked for R8 and N8
7e. R9C56 = [30] -> R9C7 = 4 (cage sum)
7f. R79C8 = 7 = [25]
7g. R9C1 = 8 -> R8C2 + R9C3 = 9 = [72], R9C2 = 1, R7C1 = 0
7h. R12C1 = {12} -> R2C2 = 4 (cage sum)

and the rest is naked singles.

1 0 3 4 5 7 8 9 2
2 4 8 0 9 1 5 3 7
7 9 5 3 8 2 1 4 0
9 8 1 2 7 4 3 0 5
3 5 7 9 0 8 2 1 4
4 2 0 5 1 3 9 7 8
0 3 9 8 4 5 7 2 1
5 7 4 1 2 9 0 8 3
8 1 2 7 3 0 4 5 9