how to limit requests made by webworker in angular

Currently in my Angular project we upload batches of files using the webworker. It turns out that the webworker can make up to six requests at a time (depending on the browser from what I’ve read on other forums), however my backend only processes one request at a time, so depending on the processing time to return the response to the frontend ( despite being a promise) ends up exceeding the waiting time.

As a stopgap, I added a 1-second timeout between requests on the frontend so the backend had enough time to process and return the response.

What I would like to know is if I can reduce these simultaneous requests from the webworker? For example, instead of 6 requests at the same time, limit it to 3?