Already exists - resource need to be imported into the State

Terraform Providers Azure
1

I have created a resource as follow

     resource "azurerm_resource_group" "my-rg"{
     name="my-rg" 
     location="West Europe"
  }

resource successfully created in Azure, now I added one more resource group in same tf file with different name

Now, I get below error

already exists - to be managed via Terraform this resource needs to be imported into the State. Please see the resource documentation for “azurerm_resource_group” for more information.

Seems like I need to do something related to state file. but not sure how?