Although OP don't worry about anonymity, AFAIK they require you to link credit cards and might be problematic for OP if he don't have any credit cards.
Though I really don't remember anything about this(because I've been using Vultr for so long), I don't think I don't have a credit/debit card connected; though I have my personal PayPal connected. Completely up to OP if he/she's comfortable with this.
Interesting. Can't comment on it though because I've only tried a Windows 7 .ISO.