Hi @AbhiAbhishek,
The back-end roles are not asigned to your user.
Looks like you are mapping your OpenSearch roles to your user using back-end roles (alternatively you can use username),
you will need to find a way to assign values (such as groups) to your back-roles in your LDAP authz configuration (Active Directory and LDAP - OpenSearch Documentation) depending on your LDAP and its configuration. I can see that the troubleshooting is being continued here: Can't map ldap group to admin roles
Best,
mj