Athena Data source not available in Grafana

Kindly follow the below documentation, for the prerequisites of configuring Athena datasource in Grafana and also tag the Athena work groups with GrafanaDataSource: true

[+] https://docs.aws.amazon.com/grafana/latest/userguide/Athena-prereq.html

Should there be a need to troubleshoot the issue further, you would be required to collect some more live data points and a HAR capture of the scenario [1], and reach out to the AWS technical Support with a support case as this may also be need to be investigated in coordination with AmazonManagedGrafana internal team.

References - [1] https://aws.amazon.com/premiumsupport/knowledge-center/support-case-browser-har-file/