DatapawWolf, Thanks for your question!
The result of "generate" method is an 2D array of cells. Drawing methos is just for demonstration, you able to make another one! Generation and drawing are completely separate.
An answer:
Tilemap is a 2D array too, so yes, you can implement it with your own tilemap. But this template don't use tilemap. There is just a sprite with frames.
Hope, this help!