Resource Android Authority found on the website of the Chinese company OnePlus, the page that is responsible for unlocking bootloader. At the moment it is inactive.
Page for unlocking the bootloader is a common practice among the contemporary manufacturers of devices on Android. She takes requests for special codes that allows to unlock the bootloader to obtain root and install custom firmware.
It is assumed that the page is for OnePlus 6T, which will be sold in the salons of the American mobile operator T-Mobile. The presentation of the smartphone is scheduled for October 30.