I ran into some issues with connecting my laptop to my tv. This is general to linux but I'm marking this as nixos because that's the laptop I ran into these issues on.
I had to use xrandr to find the displays:
xrandr
This will list all the video outputs:
eDP-1 connected
DP-1 disconnected
HDMI-1 disconnected
HDMI-2 connected
You can use arandr to manipulate the displays grapically. For my case, I used xrandr directly.
xrandr --output HDMI-2 --same-as eDP-1
This will duplicate my laptop screen to HDMI 2.
Audio was a bit harder and I'm still not sure what's wrong.
List out the audio devices:
aplay -l
To get the HDMI to work, this command I basically used without looking at the previous output so I'm not sure why it's working.
pactl set-card-profile 0 output:hdmi-stereo
alsamixer didn't seem to do much and I'm stuck trying to install pavucontrol on nixos still.