By default, any imported canvas asset to your app will not include any associated data types. Instead, for repeating groups, you'll see we use a data source called Arbitrary text.
Using Arbitrary text allows us to pass a string of text that is concatenated and :split by allows us to define a delimiter to separate the text string. Using this method, we can generate dummy content for the repeating group without referencing any app data types.
Simply clear everything in the repeating group data source, update the type of content to reference your app data type, and add a data source (e.g Do a search for [data type].
Here's an example of how to update the data source in standard data table block: