You probably installed the virtual machine version of XAMPP (e.g.
xampp-osx-220.127.116.11-vm.dmg). It does not run natively on your machine, but inside a box and with its own local network IP address. It cannot be reached via
127.0.0.1 by default, because they only refer to the host system. The guest system should be seen like another machine in the LAN.
You can find the IP address of the guest system in the General tab of the XAMPP app. In my case it is
192.168.64.2. If I enter that in a browser then I get redirected to the XAMPP dashboard (Welcome to XAMPP for 7.4.4-0).
You may enable port forwarding in the Network tab of the XAMPP app. Select
localhost:8080 -> 80 (Over SSH) and click the Enable button. You should then be able to reach the XAMPP dashboard via