VPN appliance username and password incorrect

I was trying to setup Acronis Cyber cloud Disaster Recovery, one of the steps involve setting up a hyper-v vm to run as VPN appliance, but during the registration, it gave an username and password incorrect error. But in the documentation mentioned "admin/admin" for username and password, i make sure there's no typo.

I unable to complete the Disaster recovery task due to this error.

Anyone encounter the same error?