Do both parents need to show 500k baht in the bank for a Thailand DTV visa, or just the primary holder?

A family is applying for a Digital Nomad Visa (DTV) in Hanoi and seeks clarity on the financial requirements. The husband is the primary applicant, and there's confusion about whether both parents must show 500,000 baht in a bank account or just the primary holder. It's noted that having a joint account would require sufficient funds, but the children can be supported by the primary holder's finances.