Oracle has not released VirtualBox for Apple Silicon hardware. The VM will detect this and quit.
You resolve it by waiting for Oracle to release VB for Apple Silicon, or you subscribe to Apple Silicon versions of Parallels' Desktop 18, or VMware to run ARM64 only guests on your M2 Pro. That means macOS Big Sur or later, or ARM versions of Linux or Windows. I pay $120USD per year for a Parallels Desktop Pro subscription and vastly prefer it to any prior VirtualBox solution.
I have a 27-in 2020 Core i7 iMac in the other room with 40GB RAM and a 1 TB internal drive. I purchased a Crucial X8 1TB SSD (1050 MB/s) that is plugged into my Thunderbolt 3 port, and on which I store all of my Parallel's Desktop guests. If I want to access the virtual machine from my M2 Mac mini Pro, I power on the iMac, and walk back to the M2 mini and use Screen Sharing to display the iMac on my 32-in LG 4K display. Since everything is on a Wi-Fi 6 LAN, I can view the Parallels VM guests on the M2 mini via screen share with quite acceptable performance.
There is also UTM, a VM product that will run on your M2 Pro that can host X86_64 operating systems via (quite slow) emulation and with less features than the aforementioned commercial VM products.