External display turns off a few seconds after I close my MacBook Air

I have my external display hooked up to my MacBook Air (11” Early 2015 currently running Catalina) but even if I do it before or after startup it just turns off after a few seconds. My MacBook is connected to power and pressing on any keys on my external keyboard and mouse don’t seem to do anything. Am I doing something wrong or is it just straight up incompatible?