Shut down your Mac and open "Recovery mode" (press the power button until you see this window). Click "Options". Open Utilities > Startup Security Utility and click "Security Policy".
Open Utilities > Startup Security Utility and click "Security Policy".
Check “Reduced security” and select “Allow user management of kernel extensions from the identified developers”. Restart your device.
Note:pCloud Drive requires the installation of the system extension "macFUSE" from the developer "Benjamin Fleischer" in order to run smoothly. During installation, you will be required to enable the system extension from the Security & Privacy settings of your device. The system extension is not harmful - without it, pCloud Drive will not behave properly.