Hello,
Could you provide the exact command you are executing?
Please also share a screenshot of the registry keys located at:
HKLM\Software\RCDevs\OpenOTP-CP after installation.
Additionally, set the registry key debug_mode to 4, then perform a login attempt and send the resulting logs from:
C:\RCDEVS-LOGS\CP.log
https://docs.rcdevs.com/openotp-credential-provider-for-windows/#endpoint-could-not-be-initialized
Regards,