canon makes a br e1 remote watch it on youtube works great on 6d mark 11

You can see how it works on youtube,

Sorry to hear the br e1 wouldnot work. You have to pair it in blue tooth then set shutter on 2 sec timer .
It fires straight away not after 2 seconds just for pairing reasons.
The guy at the camera shop must not know how to work it.
I use mine on my 6d mark 11 everyday.

I have a 6d mark 11 and it works perfectly.

Canon makes a great remote called br e1 it works on blue tooth so you dont have to use line of sight. You can take photos from any direction even from next room.