Create a list / things from User's list

Hello, community,
I need help.
I have a platform with members that is growing daily, and it takes a long time to create the monthly fees.
Currently, I click a button that triggers “Schedule API workflow on a list” and then a backend workflow “New API workflow”. But this method is giving errors.
Does anyone know a better way to do it? I imagine creating some kind of JSON and then uploading it in bulk. But I’m just guessing.