Its pretty high tech. You gotta copy the URL to the GIF file and paste that URL into your note.

https://media.tenor.com/lNMyjjSWLYcAAAAd/my-man-my-man-denzel.gif  

 https://tenor.com/biZPD.gif 

 Trying again?

https://tenor.com/view/funny-dogs-cute-smile-like-this-pet-gif-16881575 

 Imma hold off for now.