New Outlook synching to Microsoft servers

Just on a whim I hit the ‘try new outlook’ on my desktop Outlook (Microsoft 365) today just to take a look. Well, during setup it informs me that it will sync all my email to Microsoft servers. I do NOT want all my email synced to their servers. Does anyone know how to revert back to desktop Outlook without going completely through the setup and letting it sync? There doesn’t seem to be any obvious way to do this.