Hi Tony, Microsoft 365 E5 Developer subscription is quite enough to get this function, referring to this document: License requirements and pricing.
However, Microsoft Graph: Connectors for Microsoft Search is a new feature currently in the status of Rolling out and the initial rollout will be to customers configured for Targeted Release.
Please make sure you have enabled Targeted release for your tenant to get this function in time via Microsoft 365 admin center > Settings > Org settings > Organization profile > Release preferences.
If an Answer is helpful, please click "Accept Answer" and upvote it.
**Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread. **