Many websites that offer financial services (such as banks and investing companies) let you connect your accounts to other software, such as Quicken. However, it’s often unwise to let any third party see your login credentials. The workaround is that you can start at the app, which switches to a browser in which you log in directly to the site in question and authorize the conduit, and then the site provides a token directly to your app to allow data to flow.
I’ve found lately that this process fails as often as it succeeds when I use Safari. Apple has added more privacy protections with each successive release of Safari, and version 18 for macOS (released as part of macOS 15 Sequoia and to previous versions of macOS, like 14 Sonoma) seems to break some banking sites authorization loops.
The trouble is that the app-to-browser authorization process doesn’t reveal a URL you could copy and paste in another location: the app opens a web page in the browser. The solution is to change the default browser on your Mac to another one that is built differently, like Google Chrome or Firefox.
Read more at Macworld.com