So I was working on my game, and when I called a function I made, it said it wasn't a function.

I checked to see if I missed the function part of the code or maybe misspelled anything, and I couldn't find anything. If you need the code, it's here at Main and Level1: https://microstudio.dev/i/JustNitro/wreckoftheseas/

I'm not getting that warning.
What is the name of the function it is complaining about?

It's complaining about drawLevel1, and you have to press enter, go right, press enter, then press enter once more. That makes it complain about the function when calling it.

I checked your code, there is actually a missing "end" to close the function updateBoss1

updateBoss1 = function()
  
  (...)

  //Dying
  if gas < 0 then death = 3 end
  if x < -175 then death = 1 end
  if x > 175 then death = 1 end

// end is missing here!!!!

drawBoss1 = function()
  screen.clear("rgb(0,0,80)")

Due to this mistake, the function drawBoss1 is not defined before updateBoss1 is run for the first time. There is an end at the end of your file which you need to move up to the location of my comment above :-)

Thanks! I didn't see that before, I fixed it and now its fine.