Sharing Amazon Managed Grafana Dashboards: How to authorize someone to view?

I have used Amazon Managed Grafana to create a dashboard that I would like to share with a friend. I selected "share" and created a link. However, when my friend attempts to open the link, they are redirected to:

Welcome to Amazon Managed Grafana

Sign in with AWS IAM Identity Center

So here's where I am confused. Does my friend have to create an AWS IAM Identity center account to view the dashboard? How would they go about doing that?

Cheers, David