Looking for Help: Programming Mouse Side Button for 'Shift + Click' Functionality

Hi all, I have a Logitech MX Anywhere 3 and am interested in having one of the side buttons execute "shift + click", within a certain app ideally but it's okay if it's system-wide. The mouse is connected via Bluetooth. Any ideas on how to achieve this?

I have a different Logitech, but does yours work with the Logi Options app? If so, you can just set it there (either globally or for a given app):


That worked! Thank you!