is 'coprime' available in lean4?

Stream: lean4

[Matsushima Yasushi]

I have tried unsuccessfully to run the sample code I found online. Here is code
Error says "invalid field 'coprime', the environment does not contain 'Nat.coprime'"
I use lean4:nightly-2024-02-05 and Mathlib4.
Indeed, There is no method in both library named 'coprime'. But I found this method in Documentation. I thought maybe it has something to do with the white color of the outer frame of this method in Documentation. After all, I would like to know if it is possible to use the coprime method, and if so, do I need to add a new library or something?

[Ruben Van de Velde]

Capital C