Vero4k won't start, Red led on

Well as a quick test you could use a USB A-A Cable to power the Vero.

Also find the details for the Power Supply.
Some time ago @sam_nazarko provided some links how to order them within the osmc shop, see his post

https://discourse.osmc.tv/t/vero4k-power-supply/87080/5

Other way would be to get one somewhere else, specification: DC 5V, min. 2A, center positive, coaxial power connector male with OD 5.5mm and ID 2.1mm