I have a VicTsing USB 3.0 to hdmi donggle, but it doesn work with elementary, do you know any donggle compatible with this sistem, I just have 1 hdmi and I use 2 monitors. Thank you
Here is a link that has some good info on what you are experiencing.
"I have a Dell Inspiron 15 7537 with nvidia primus disabled, so it's only intel graphics. I have a triple-monitor setup; laptop screen + Dell 1080p (HDMI) + Dell 1080p (USB->HDMI (DisplayLink) -> DVI (generic adapter)). Dell D3100 and CableCreation adapter work for me. I use v4.2 driver on Ubuntu 18.04 with this workaround."
Hope this helps man.