Hi William,
The app seems to be pointing to a Dataverse Table.
In case you want it to refer back to your List, you can try the below steps:
Click on Add data that you see in your image, and search SharePoint and create connection.
To provide the SharePoint URL, open your Microsoft List and Copy the link
from https://......... up to /Lists
Example : https://contoso-my.sharepoint.com/personal/admin_contoso_onmicrosoft_com
This will give you your List and you can select your list - x300 Proof of Concept
I would also advise you to take a copy of the app before you try this out, since this might cause issues if column names of Dataverse table and your List are different, which you might need to find and fix further.