Hello Dmm23
Hi, I'm Karl and will be happy to help you today.
There is only one link to access the classic view that I'm aware of which is
https://outlook.live.com/owa/?path=/classic
Just tested this prior to responding and it worked as expected (the attached screenshot shows the same account in both classic and standard view). Tried it using both MS Edge and Chrome.
If it doesn't work for you, would suggest trying accessing it using a private browser session or a different browser
Note: at some point, it is very likely that the Classic view is going to get removed without any notice since what you refer to as the <new> version has been around for quite some time.
Just so there is no misunderstanding, this is a public user-to-user support forum. We're users just like you helping other users. We don't work for Microsoft have no input on Microsoft's policies, procedures, or design decisions. Microsoft Support personnel do not staff this forum.