Adding a GIF directly to the user's profile is not possible.
1️⃣ Replace the profile picture with a GIF
To add a GIF instead of your profile picture, here are the steps to follow.
Start by making an additional field visible in your settings.
You need to have the access link to your GIF. To do this, you can retrieve the link from where your image is stored.
Once you have retrieved the link to your GIF, enter it in the field you added.
Save your changes and go to the template of your choice. Once your template is selected, add an image block. In the source field, you can add your attribute.
Automatically, the signature will retrieve the link of each user to apply their Image.
For those who do not have an image, you can set up an {{if}} condition on the image.
Example:
{{if extra_field_user}} YOUR IMAGE HERE {{endif}}