Hello @PratikRudra 

Thank you for sharing the error: 

I think probably there is a component that is missing. Writing table metadata (for example, to the _delta_log directory) requires the CREATE EXTERNAL TABLE capability on the external location; this privilege is distinct from volume or browse permissions. It guarantees that Delta tables at paths controlled by that external location can be managed by the principal.

For this: check what permission you have by running this sql query

SHOW GRANTS ON EXTERNAL LOCATION your_external_location_name;

Also run 
SHOW GRANTS ON SCHEMA main.default;

Also make sure that the storage account has sufficient Azure RBAC roles like Storage Blob Data Contributor