How to connect to Managed MongoDB instance from Grafana's MongoDB plugin?

I have tried everything I could think of to get MongoDB visualizations in my Grafana Cloud. Grafana has an option for a “Private Datasource Connect,” which creates a VPN tunnel, however, since it’s a managed MongoDB instance, I cannot ssh into it to install an agent. So, I added all 47 current Grafana Hosted Metrics IPs to the Trusted Sources of my db cluster, thinking it was a firewall issue, but that still did not work.

I receive this error in Grafana:

The connection can not be established. Error: server selection error: server selection timeout, current topology: { Type: ReplicaSetNoPrimary, Servers: [{ Addr: <my-cluster-name>.mongo.ondigitalocean.com:27017, Type: Unknown, Last error: dial tcp <my.ip.address>:27017: i/o timeout }, ] }

The credentials are set in the Authentication section, and my connection string is mongodb+srv://<my-cluster-name>.mongo.ondigitalocean.com/admin?authSource=admin&replicaSet=<my-cluster-name>

Grafana does not accept the mongodb+srv://username:password format. Surely I’m just doing something incorrectly and there is a way to get visualizations for my managed Mongo instance in Grafana?