@digital.search you have already created a thread regarding this: Www. redirect issue
As @hrishikesh explained, netlify.app subdomains are <site-name>.netlify.app and www.<site-name>.netlify.app is not configured and therefore not a valid domain.
There is no such setting for a netlify.app domain on paid tiers either.
As explained (again in thread linked above) there is no way to accomplish this.
When you added your site to Google, did you add it with or without the www? If you added it with it, you should remove it and add it again without. If you added it without, then I suggest the issue is with Google and you should try contacting them.
Alternatively, as @B00bleaTea suggested, you could use a custom domain.