Documentation:

The instructions for adding Payments users needs a refresh. It hasn't been updated since we took on Terraform.
https://github.com/cal-itp/data-infra/blob/main/runbooks/workflow/payments/add_agency_dashboard_data_source.md

If it makes sense, it can point to PRs that describe the process.

Expectation:
A low level developer or analyst can read the documentation and example PRs and replicate the process to add a new payment user.