401 error when Synthetic Monitoring Application (worldping) in Self hosted Grafana

What happened?

I have a self-hosted Grafana instance running on AKS in Azure. I followed the instructions here: Synthetic Monitoring plugin for Grafana | Grafana Labs

I created an API key on my grafanaDotCom account with Admin permissions as stated in the instructions.

When I “initialize”, I get a 401 error

What was expected to happen?

I was expecting the installation to complete as per the instructions

I am running Grafana 7.06, it has 2 plugins. Azure Monitor and PostgreSQL installed.

Also, please let me know how I set up the billing if I want to upgrade from the free tier of worldping, is that done in my grafanaDotCom account?