Form : Undefined variable: name

Hi there,
I followed exactly what it is explained here : Email contact form | Kirby CMS to create a simple form.

On local, I have a success message
But after deploying the site on live on my server, I get an ‘Undefined variable: name error’.

Any idea what the issue can be?


Is there any stack trace? I.e. from which line in which file the error originates?

Unfortunately no, I have no error in the console.
Thanks for your help

Where does the error show up then?