Nodejs - How to copy files between two S3 buckets in different accounts

I've a node.js program that is responsible to copy files from Bucket A belonging to Account A to Bucket B in Account B. How can I achieve this? My program runs fine when both buckets are in the same account. Here is the snippet of code:

async function CopyMyFiles(fileID){
    const s3 = new AWS.S3({
        secretAccessKey: process.env.ACCESS_KEY,
        accessKeyId: process.env.KEY_ID,
        region: process.env.REGION,
     });


     const params = {
         Bucket: BUCKET_DEST, 
         CopySource: "/" + BUCKET_SRC + "/" + fileID, 
         Key: fileID
     };
  
    
     await s3.copyObject(params, function(err, data) {
           if (err) {
             console.log('error', 'Error occured while copying', err); 
           }
           else{
             console.log("S3 file copied!"); 
           }
    });    
}

My confusion is how to provide credentials to source and destination accounts here? Is just providing the CopySource enough in here for this cross-account scenario?