NextJs - Use fetch() to make api call with POST method - always ERR_ABORTED 400

when I try to make api call with fetch() method and request type is POST, then I receive error in console: "POST ... ERR_ABORTED 400 (Bad request)"

btw. I have used 'no-cors' mode because api url is on different domain, I know that this is not best approach. For now I just want to make it to work and later I will deal with CORS issue that I have when mode is not set to 'no-cors'.

    const res = await fetch(apiUrl, {
    method: 'POST',
    body: JSON.stringify({
        sku: sku
    }),
    headers: {
        'Authorization': 'Bearer ' + jwtToken,
        'Content-Type': 'application/json'
    },
    mode: "no-cors"
});

What can be the cause why fetch() method always returns error, maybe something with the syntax? Both "sku" and "jwtToken" variables are set.

I tried it with postman and everything works fine, but when I try to make that api call inside nextjs then its not working.