Data source is not working with Oracle Cloud Infrastructure for the grafana deployed on OKE

I have deployed my grafana on OKE cluster by using the below documentation. Deployment is success and I am able to connect to the grafana.

I am facing the below error while adding the DATA SOURCE Oracle Cloud Infrastructure Metrics.

Here I am sharing the error logs from the grafana kubernetes pod. Please check and help me to resolve the issue.
logger=context userId=1 orgId=1 uname=admin t=2023-08-25T07:27:51.294591759Z level=error msg=“Internal server error” error=“[plugin.downstreamError] failed to query data: Failed to query data: rpc error: code = Unknown desc = Error returned by Monitoring Service. Http Status Code: 404. Error Code: NotAuthorizedOrNotFound. Opc request id: bbc7703c2c681868a723e85a23d7cf9f/5E3C42CDB97FB0D7B5BD478EC81E56D8/858ECF12E9A5D416B46174527B6275B6. Message: Authorization failed or requested resource not found.\nOperation Name: ListMetrics\nTimestamp: 2023-08-25 07:27:51 +0000 GMT\nClient Version: Oracle-GoSDK/65.23.0\nRequest Endpoint: POST
apierrors_404__404_notauthorizedornotfound for more information about resolving this error.\nTo get more info on the failing request, you can set OCI_GO_SDK_DEBUG env var to info or higher level to log the request/response details.\nIf you are unable to resolve this Monitoring issue, please contact Oracle support and provide them this full error message.” remote_addr= traceID=