Custom User-Agent disrupts functionality on Safari

[nothowstorygoes]

What

• I'm developing a nutrition PWA to expand my portfolio using your database for nutrition values of products. I have set a custom user agent as per your request from the documentation, but using a custom user agent on ssafari blocks the fetch request and returns no response.
  On chrome it works fine, even though the User Agent is the default one as you can see on the network tab below. On safari the custom User-Agent blocks the request.

Additional context

This is the user agent on chrome

customUserAgent is a string contaning the requested infos.

code : response = await fetch(
https://world.openfoodfacts.org/cgi/search.pl?search_terms=${productName}&search_simple=1&action=process&json=1,
{
method: "GET",
headers: {
"User-Agent": customUserAgent,
},
}
);