Kirby doesn’t work on the server by my client

Hello, I created a website with Kirby.
When I make Kirby’s website, it generally works well,
but it doesn’t work on the server by my client.

So the server developer wants to talk to Kirby.
I’d like to ask you where to talk, not at the forum.

The client’s message to me is as follows.
Since I don’t understand the server well, I think it would be better to connect directly with Kirby’s developer.

Could not update the integration plugin

Looks like they want to install or update something via composer and that doesn’t work on the server. Imho something that has to be fixed by the server admin.

But maybe it’s in general a better idea to build an update/deployment workflow. Deployment via git, run (and test!) updates locally before doing it direktly on production, for example.

And what is the integration plugin?