Hi praveen Thanks for reaching out. From the error message, it seems that the client with the object ID you specified does not have the necessary permissions to perform the 'Microsoft.ApiManagement/service/apis/write' action over the specified scope.
You mentioned that you have given the necessary permissions to the app and users, but it seems that the permissions are not sufficient. Please ensure that the client has the 'Microsoft.ApiManagement/service/apis/write' permission over the specified scope.
You can check the permissions of the client by going to the Azure portal, selecting the API Management service instance, and then selecting 'Access control (IAM)' from the left-hand menu. From there, you can check the permissions of the client by searching for its object ID.
If the client does not have the necessary permissions, you can add the 'Microsoft.ApiManagement/service/apis/write' permission to the client by assigning the 'Contributor' role to it at the API Management service instance level.
I hope this helps! Let me know if you have any further questions.