My trick tomorrow is figuring out how to connect 3 external monitors (2x4k and 1x1080) to my work laptop (lenovo t490). So far, I can get any two to work, but not 3
@jerry likely not supported by the hardware. Only option in that case is to use a displaylink adapter for the third display.
What it does is create a virtual display that's then fed over usb to a dock that can then output to a real display. Its not fast and eats up cpu resources so stick to the 1080p display on it