How to update Safari with an old OS High Sierra?

Mostly you just need a more modern Browser than Safari on Mojave, or High Sierra like Firefox or Brave.

https://brave.com/

https://www.mozilla.org/en-US/firefox/83.0/system-requirements/

Firefox 83.0 System Requirements (mozilla.org)

Opera…Thanks

https://www.opera.com/download/requirements

Opera system requirements | Opera

Thanks to dialabrain…

Firefox 115 is now the current version. runs in High Sierra.

https://www.mozilla.org/en-US/firefox/new/

Thanks to A Brody, Browsers by Mac operating system…

Browsers by Mac operating system - Apple Community

These days, installing a newer version of macOS is the only way to get a newer version of Safari. (When Safari was new, Apple distributed it by itself, for Macs and PCs, but that was a long time ago.)

There are alternate browsers, like an Extended Release Version of Firefox, that will run on High Sierra and that may be a bit more up-to-date than High Sierra's version of Safari.

Back up your data, check the application compatibility table, click here, and then on the download link for it. Alternatively, use a different web browser for those sites.

Catalina and above won't run 32-bit software; if you choose one of them, use Go64 as well.

(244946)