I had this error while installing the Joplin server on a raspberry Pi.
WARNING: The requested image's platform (linux/amd64) does not match the detected host platform (linux/arm64/v8) and no specific platform was requested
Maybe the docker arm64 should be made available ?
@Guiraud welcome to the forum.
Joplin only distributes an amd64 server docker image however others use automatic tools to make docker images available for arm64 & arm/v7.
This post has further details (server is towards the bottom of the post):
I have used both of the arm64 versions shown with no problems.
If you need additional help with installing Joplin-Server on a Raspberry Pi, take a look at this threat:
Kind regards