I do not have an iMac. I connected this monitor to an older MacBook Pro (2012) (https://support.apple.com/kb...).
To make this work, I also ordered this cable Delock Mini Displayport 1.1 - HDMI (https://www.digitec.ch/de/s1/product/delock-mini-displayport-11-hdmi-2m-hdmi-display-port-video-kabel-5655732). I connected this to the Thunderbolt port on the MacBook.
However, the iMac 2019 has Thunderbold 3 ports according to the site https://support.apple.com/de-de.... I assume it should work with such a cable https://www.digitec.ch/de...
But unfortunately that's just a guess. Maybe someone else has concrete experience with the iMac 2019.