MacBook Pro A1706 only has black screen, ESC key sometimes on touch bar

See if the laptop qualifies for this free Apple backlight repair program:

https://support.apple.com/13-inch-macbook-pro-display-backlight-service

FYI, here is a current list of all publicly acknowledged free repair programs for various Apple products (some have multiple programs):

https://support.apple.com/exchange_repair

Also if the display has a problem, then usually you have to force the laptop into Clamshell mode in order to have anything show up on the external display (it can be difficult to get video on an external display). Another option is to give the laptop time to boot to the login screen. Then press the first letter of the user name then press the "Return" key. Enter the password and press the "Return" key again. Once logged in you should see video on the external display. With a Touchbar model you can try toggling Mirrored displays by first holding the "Fn" key then pressing Command + F1.

Also if the laptop has the backlight cable issue sometimes you can close the lid and very slowly & carefully open the display to about 20 degrees to see if the display lights up. You can do this while the laptop is booted as the backlight can sometimes be restored. If you open the display to around 45degrees then the backlight may go out due to a defective cable.