Character function like CHR (ascii_code_number)

Need help
30

I change the function to:

module.exports = function(context, cb) {
cb(null, String.fromCharCode(context.query.code))
}

It’s OK then. In the Bubble Editor for a Text element, if I choose “Get data from external API” then I can see “Char - Code” in dropdown menu. When I choose this, I think I can assign a code for this function, but I got only “Char - Code’ 0”. I don’t know why.