Normal sudoku rules apply.
A number outside the grid is the sum of all the digits between the 2 and the 3 in the corresponding row or column.
Pick any square with a 4 and the sum of all squares that are orthogonally adjacent to that square will always be 26.
Example:
On the left we see that the numbers between the 3 and the 2 adds up to 8.
In the middle we see that all the numbers orthogonally adjacent to the 4 adds up to 26.
The puzzle:
solving online: penpa
Solution code: Row 8 and 9, from left to right, no gaps between numbers.