Recovery of broken BitLocker

Goodmorning everyone


I ask for help for a problem on a windows 10 computer with Sophos Safeguard where it asks me to Plug in the USB driver that contains the Bitlocker recovery key, but when I go to export the key from the console following the instructions described on the link https://community.sophos.com/kb/en-us/121423 shows me the button in gray, I checked the registry key and verified that I am admin mso and it is as described in the article. Also if I try to recover it asks me for the Challenge that I can't get.

Is there any way to recover the computer?

what are the cases in which, despite what is described at the link community.sophos.com/.../121423, I cannot select the export key button?

The pc is a HP Elitebook 830 G5 with Windows 10 Pro (64bit) Build 10.0.14393.447 Version 1607 Sophos SafeGuard Client 8.00.4.8

Thanks for your help
Franco