With ModelDrivenFormIntegration an embedded canvas app are able to perform a few operations on its model-driven host. Read more about that on Microsoft Learn.
This control does not appear automatically when using the modern UX to edit your app. There seems to be no supported way to add or enable it other than going through the classic interface recommended by many community posts (as of Feb 2024).
The fix is quite simply to add &is-hosted=true to the url of your Canvas App Editor. This makes the ModelDrivenFormIntegration control available.
Happy (low-)coding!