Wiring combination: AC powered switching DC source.

Since shelly output is a relay and schematic is depicted in:

https://kb.shelly.cloud/knowledge-base/shelly-plus-1

as

Can be connected as follows:

Powered by AC phase voltage, using phase voltage as switch.

Shorting (closing) a DC circuit, being DC from lets say 1V (<0V) to rated DC voltage.

A) FLOATING DC:

B) GROUNDED DC:

I've consulted some diagrams available of the "1" version (about 12 wiring diagram combinations available) but those are not among them.