CORS error message on api merge call

Which product are you using?
PDF.js Express Plus

Detailed description of issue
Access to fetch at ‘ ’ from origin ‘[domain)’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource. If an opaque response serves your needs, set the request’s mode to ‘no-cors’ to fetch the resource with CORS disabled.

getting this error

// Process the file
const response = await fetch(‘ ’, {
method: ‘post’,
body: data
}).then(resp => resp.json());
const { url, key, id } = response;
const mergedFileBlob = await fetch(url, {
headers: {
Authorization: key
}).then(resp => resp.blob())