In that case, you could Run the program, and instead use the Console to code. It won’t save it to the file, but I think it’s more similar to what you’re looking for.
I’m not sure why you want to add line numbers to the file, that is not necessary in an IDE, as you can see the line numbers on the left side of the code editor.
Call me old fashioned. I have some really old classic BASIC code that still uses line numbers for reference: GOTO 220, GOSUB 400, that kinda thing. Now, I could convert that to use labels and not line numbers, but I don’t want to right now - I want to run that old code as is. I have local BASIC interpreters that can do that, but I was hoping for something in the cloud. Look like I will have to use QuiteBASIC instead.