To create a rule, go to the New Rule page. You can create a rule from scratch by selecting an empty rule, or use one of the existing templates. These templates are written by Auth0 to assist you to in executing common tasks.
For this example, select the Add country to the user profile rule.
This rule extracts the country_name from the context and adds it to the user profile as a new country attribute.
This is just the beginning, you can edit the rule to meet your business needs. Once complete, click Save. The rule will execute any time a user logs in, and the country will be added to the user's profile.