CodeMirror in Vue - How to access to the API with Vue

Hi all,
I installed with npm codemirror on my Vue and it works fine.
So now I need to use APIs.
How can I get an instance of it?
I have the component

export default {
  components: { codemirror },

and I can access it … it’s ok.
but if I call a function like this:


it does’nt work!
what is my mistake?
Bye and thanks.