403 ERROR the request could not be satisfied unable to download paid subscription to Racenet

It is a code to say you are not allowed access. Try clearing the cache for cookies and data for that site and start afresh Settings > Privacy and security > Browsing data > Clear data for specific site. There could be other settings you have or it could be their end. I see you are using Win 10 which may have outdated security checking options, I read somewhere , here, there is a free upgrade to Win 11 if you want to try, but that would mean a whole reset so you would want to copy all your data etc. including for example your Firefox profile