This has been arnswered well in this post already. You should be able to make progress by studying that some more, simple enough when you get the hang of it.
https://fxdreema.com/forum/topic/16167/easy-way-to-make-enum
Looks like your constant is set wrong, your conditions are requesting 0 and 1 as identifiers so change your "exit_mode" from "fixed" to a "0" or "1".
Also no spaces in your "exit_mode_list" make it so it is like this "{fixed,break_even,trailing_stop}
a3afd2ff-ef20-440d-a9b8-7e371688d456-image.png
