Last month Canva was breached. As part of their response, Canva partnered with 1Password to offer 12 months of the family plan for free. New 1Password customers only.
Credit to @carlucch for the updated link after 1Password and Canva added extra hoops for users to jump through.
They have a paid version and enterprise which should able to sustain him to keep developing and server cost for free users.
It doesn't take up much space for a normal consumer individual account.