How to retrieve SharePoint List items via Microsoft Graph REST API
- Establish a Microsoft Graph Connection  (for more details, please check here); 
 
- In the REST Source editor:
 
- in the Connection box - choose the
established Microsoft Graph Connection (e.g., REST Connection Manager 1     in the screenshot below);
 
- for Resource  choose Site | List
Item from the drop-down menu; 
 
- for Endpoint  leave the <default>; 
 
- in
Parameters  in the list_Id forValue - you can choose the list
you want from the drop-down menu (see the screenshot below):