Greetings @Dar4Char ,
Unfortunately, to add the Canva integration, you must have the Admin functionality inside of canvas to fully add this feature. However, you could always use the ReDirect tool app inside of canvas and link canva there, that's another option.
Feel free to check this out, this may assist you. https://www.canva.com/help/connect-to-canvas/
Reach out with any questions.