I think it should work with Node 20 locally, but for now we don’t officially support it (we talked about it here: Passage à NodeJS 20 )
In any case the integrations are in the repo, and when you run npm install it installs the integrations’ dependencies 
I still advise you to set the variable INSTALL_SERVICES_SILENT_FAIL if you are not developing on Linux, because some linux-only dependencies will probably have trouble installing:
(See doc: Mettre en place un environnement de développement sous Mac/Linux | Gladys Assistant )
This parameter is just a flag to say it’s okay if some integration dependencies are not correctly installed, since you don’t necessarily want all integrations to be functional locally.