No acces to backend file via url "_functions/ping" or other file

Question:
why do not get acces to a backend file, in my case “UpdateWorkout.web.js”?

Product:
i use wix editor premium acces

What are you trying to achieve:
I try to import data from make.com http module to my cms but i cant get acces to backend file.

What have you already tried:
i tryed to create jsw file, web.js file but no acces

Additional information:
this is my code in my web.js file:

import wixData from 'wix-data';

// POST  https://DEINE-DOMAIN/_functions/updateWorkout
export async function post_updateWorkout(request) {
  const options = { headers: { "Content-Type": "application/json" } };

  try {
    const { itemId, updates } = await request.body.json();
    const updatedItem = await wixData.update("WorkoutDaten", { _id: itemId, ...updates });
    return new Response(JSON.stringify({ success: true, item: updatedItem }), options);
  } catch (error) {
    console.error("updateWorkout Fehler:", error);
    return new Response(JSON.stringify({ success: false, error: error.message }), options);
  }
}

i hope someone can help me out. i would also pay for your time and help. best regards Bernhard