You can easily locate TpT resources that are enabled for Easel using the “Easel Activities” filter on the left-hand side of the TpT homepage, under the “Digital” category. See screenshot below:
If a Teacher-Author has already prepared a Easel Activity for the resource, you’ll see this “Easel Activity Included” label in search results:
If a resource is enabled for Easel Activities, but doesn’t include a pre-prepared activity, you’ll see this “Compatible with Easel Activities” label in search results: