xdotool export bad variable name

I have a probably very simple problem, but it's taking a lot of time and I can't seem to find a good solution.

I'm using fusuma on my laptop to use gestures on my touchpad and for that I want xdotool to execute some keypresses.

When I execute this alone in a terminal, it works as expected:

xdotool key ctrl+alt+Left

But in my fusuma config file the following code doesn't work, while it did on my previous laptop

command: 'xdotool key ctrl+alt+Right'

It then says:

Error: Can't open display: (null)

So I found that I should use this:

  command: 'export DISPLAY=:0.0 xdotool key ctrl+alt+Left'

But then it says this:

sh: 1: export: ctrl+alt+Left: bad variable name

Does someone see what goes wrong here? Any help is appreciated.

Jack