Is there a way to show the due date on a card while posted on the Kanban board?

By default, cards show the number of days remaining till the task’s due date, and the date itself is visible when you hover the mouse pointer over the calendar icon on a card.

Additionally, you can project the full due date onto card fronts with the Task Summary power-up.

If you don’t see a due date field on your cards, then go to Settings - Card Template and enable the field.
Please note, board Settings are only accessible to users who were given at least a project manager privilege or were made a board owner.