Hi,
Indeed, the pre requisite section is pretty clear about it: https://docs.xen-orchestra.com/installation#packages-and-pre-requisites
And the error message was clear too:
The engine "node" is incompatible with this module. Expected version ">=20.18". Got "18.19.1"
However, if you think there's a way to improve this, let us know, we'll be happy to assist