Choose or edit designs with Canva

• Choose from Canva: open Add media → External sources → Canva, connect your Canva account and pick a design. It's exported and added to your post.
• Edit in Canva: under an image in your post, click Edit in Canva. When you finish, the updated design comes back to the same draft.

Publishing from inside Canva is covered in the Canva App guides.