1. In the top-right corner, click the 'Open Nodes Panel' button.
2. After that, find and select 'On a Schedule'.
3. Now, set up the Schedule Trigger based on your preference. Provide the necessary details, such as Trigger Interval, In-Between Trigger, Trigger at Hour, and Trigger at Minute. Configure each menu and input field accordingly.
4. If you wish to personalize the Schedule Trigger further, tap 'Add Rule' and configure the corresponding settings according to your liking.
5. Once done, tap 'Execute Step' to proceed.
6. Go back to the workflow canvas and tap the 'Add' button.
7. Following that, head over to the right-hand panel and click 'Human Review'.
8. Browse the list of apps, then select 'WhatsApp Business Cloud'.
9. At this point, it's time to set up the WhatsApp node. To get started, click the 'Credential' menu and choose the WhatsApp app you wish to use.
10. As for the Resource, make sure that the default configuration is set to 'Message'.
11. Subsequently, click the 'Operation' menu and choose 'Send'.
12. Tap the 'Sender Phone Number' menu and select the phone number you want to use.
13. Following that, enter the recipient's phone number into the next input field.
14. Tap the 'Message Type' menu and choose your preferred option from the list.
15. Subsequently, prepare your message and type it into the 'Text Body' input field.
16. If you wish to configure your WhatsApp node further, click 'Add Field' and set it up accordingly.
17. Once done, click 'Execute Step' to run and test your input.
18. Once done, review the workflow and tap 'Publish' to activate it.
19. Provide a unique Version Name and Description. Type the details into their respective input fields.
20. Once completed, click 'Publish'.
21. Finally, sending your WhatsApp messages will be automated based on the configuration of your n8n workflow.