Redirecting to login page of Amazon opensearch with VPC enabled(fine grained with master user) even after giving correct credentials

Hello Team,

I have created amazon opensearch domain with vpc enabled. I am using fine grained access with master user/password.

To access it outside vpc I have used nginx proxy_pass as k8s deployment and service. I am able to see login page (redirection is happening) but after giving credentials, again redirecting it to login page.

upon debugging using webpage what i have found it.. ( using F12 network tab ) below are giving 401 unauthorized. _dashboards/api/ism/apiCaller Request Method: POST Status Code: 401 Unauthorized

_dashboards/api/v1/multitenancy/tenant Request Method: GET Status Code: 401 Unauthorized

_dashboards/api/v1/restapiinfo Request Method: GET Status Code: 401 Unauthorized

_dashboards/api/v1/configuration/account Request Method: GET Status Code: 401 Unauthorized

_dashboards/api/v1/auth/dashboardsinfo Request Method: GET Status Code: 401 Unauthorized

dashboards/api/dataconnections Request Method: GET Status Code: 401 Unauthorized

dashboards/api/v1/configuration/account Request Method: GET Status Code: 401 Unauthorized

dashboards/api/v1/multitenancy/tenant Request Method: GET Status Code: 401 Unauthorized

I am able to access VPC endpoints with same credentials successfully. Do i need to any extra permissions or some policy to make it work.

Please help for the above. I am stuck from past one week.