Your Partner Commerce site may require State and Country picklists. You must configure these picklists on the org level which enables the State and Country fields to display the picklists on the Contact object.

To enable state and country picklists

  1. Go to Setup, in the Quick Find box, search for State and Country/Territory Picklists, and click State and Country/Territory Picklists. The State and Country/Territory Picklists setup page appears.

  2. On the State and Country/Territory Picklists setup page, follow the step-by-step instructions to enable the State and Country picklists.

For complete information, refer to Enable and Disable State and Country Picklists in Salesforce documentation.