The company isn’t saying exactly how it’s able to do so
https://www.theverge.com/2018/11/27/18115176/drivesavers-locked-iphone-break-in-unlock
“Other companies offer a similar service only to law enforcement. DriveSavers is the first to offer a Passcode Lockout Data Recovery service to consumers. The DriveSavers service is not available for law enforcement and requires proof of ownership prior to unlocking a device.”