Issue
I want to use Heroku External Objects with Salesforce. When creating a new External Data Source in Salesforce (as detailed here), I need to select "Salesforce Connect: OData 4.0" in the "Type" field, but the option isn't available.
Resolution
If "Salesforce Connect: OData 4.0" is not an available option, it's possible that your Salesforce organization may not have this feature enabled. This is likely due to the edition of Salesforce your org is using. The Salesforce documentation on the OData 4.0 Adapter for Salesforce Connect lists the supported editions:
Available in: Developer Edition
Available for an extra cost in: Enterprise, Performance, and Unlimited Editions
You can follow these steps to determine which Salesforce edition you have.
If the edition of your Salesforce org is not one that inherently supports this feature, reach out to your Account Executive (AE) for more information on purchasing Salesforce Connect with OData 4.0 support.