How can I get 'Cortana' to remind me to do something every two hours.

Example: Ask 'Cortana' to remind me (every two hours) to buy Mum a Birthday Card.

I would like a 'Pop Up' on the Screen if possible. Audible preferred but not essential.

Unless there is another program or App in the Apps Store.

I don't want to change my Browser from Edge or download any third party software.