Wix fetch in backend throws errorNotAuthorizedError

I’v search my issue about the backend fetch fail in Google.

There was nothing that fit my situation
https://www.wix.com/corvid/forum/community-discussion/backend-fetch-function-not-working-client-says-uncaught-in-promi
However, the answer still not work for me.

Here’s my code in backend.

import { fetch } from 'wix-fetch'; 

export function myFetch() {  
    let url = 'my url';  
    let request = {method:"get"};  
    return fetch(url, request).then(response => response.json());
}

And call it in page code:

import {myFetch} from 'backend/myBackendFile'
export function button_click(event) {
    myFetch().then( (json) => { 
        return json;
    }).catch((error)=>{console.log('error' + error)});
}

The error return a message:

errorNotAuthorizedError: No permission to access the web-method myFetch in module backend/myBackendFile.jsw

PS: I tried to call same url in page with wix-fetch before, it worked. For some security reason, It have to be put in backend fetch.

Please help, thanks a lot.

Do you have the correct webmodule permissions ?