Looping M code function for ServiceNow API

Disregard. I found a solution!

Here is my working table query:

let
    Source = List.Generate(
        () => [Offset = 10000, x = function_user(0)],
        each not List.IsEmpty( [x][result] ),
        each [offset = [Offset] + 10000, x = function_user([Offset]) ],
        each [x]
    )
in
    Source

This video and article were a huge help: https://gorilla.bi/power-query/list-generate-api-calls/, https://www.youtube.com/watch?v=a_RJzoj1cnM.

Hopefully this helps someone else!