M1 mini - which cable for 2nd monitor?

[silverlakerCA]

I just received my second 24" monitor, a Dell refurbished 4K.
THEN I ran into a problem. I've only got one HDMI port on M1 mini rear - and using an HDMI to USB-C cable for my second monitor I get nothing but a black screen and an error message. I get a floating 'No DP Cable - this display will go into Standby mode in 4 minutes'

What kind of cable should I get to make this work?
I've taken a photo of the underside of the 24" that shows what connections I can use.
Really appreciate your help.

 

[estabya]

The M1 supports only a single HDMI device whether it’s from the actual HDMI port on the Mac or converted from USB-C. I would recommend just a straight USB-C cable since the monitor has it; just make sure it’s a data cable and not just power. This will also allow you to use the monitor as a USB hub.

Something like this cable should work just fine.