Give them a reasonable amount of time to respond. Buyers may be busy or have other priorities, so it's important to be patient. However, if you have not heard back from them in a few days, you can start to take action.
Send them a friendly reminder. You can contact the buyer through Fiverr's messaging system to remind them of your order and ask if they have any questions or need anything else from you. Be polite and professional in your message.
Request an extension on the delivery time. If you are still waiting for the buyer to respond, you can request an extension on the delivery time. This will give you more time to complete the order and avoid any late delivery penalties.
Contact Fiverr support. If you have tried to contact the buyer multiple times and they are still not responding, you can contact Fiverr support for help. They may be able to reach out to the buyer on your behalf or help you to cancel the order.