Hi,
Prior to Quartus Web 8.1 requires license & that you can get it from Legacy License Generator tool but beginning with Quartus Q8.1 Web & future versions of Quartus Web & Lite editions don`t required license.
Please refer the below links & keep a backup first.
https://www.intel.com/content/www/us/en/programmable/support/support-resources/download/licensing/setup/lic-setup-q2webedition.html
just provide the NIC & it will ask for email address,
https://www.intel.com/content/www/us/en/programmable/support/support-resources/download/licensing/lic-choose.html
have a look on old thread,
https://forums.intel.com/s/question/0D50P00004LH4vA/cant-get-new-quartus-web-50-license
please let me know if you have any different concern.
Regards,
Vicky