Updated 8/7/2020: The $66 credits only for Public Cloud charges.
“OVHcloud voucher for Cloud 66” $66 value add to your account with OVH Cloud. Just in case anyone need a voucher for your OVH Cloud VPS, there’s a $66 voucher you can add to your account billing as credit to use, it’s only good for 1 month, meaning next billing period of your account will be use.
More info here: https://www.ovh.com/blog/n34389vjkweyuj6vsette5/