How to define task_definition_task_role_name and task_definition_task_execution_role_name?

The YAML provided shows these two lines, but no instructions on what should be done to create these roles. Please advise. Thanks.         

"Resource":[
            "arn:aws:iam::<aws_account_id>:role/<task_definition_task_role_name>",
            "arn:aws:iam::<aws_account_id>:role/<task_definition_task_execution_role_name>"
         ]