How do I send SMS/Whatsapp via Appsmith?

This question was asked by one of our community members on Discord:

Is there a way to send SMS/Whatsapp via Appsmith? I am looking at sending transactional notifications to user.

Appsmith allows you to integrate messaging services by using the REST API integration. Follow along with this guide:

For starters, we also have a forkable template that can dynamically generate custom messages from your data using this WhatsApp link builder, then send the message to a WhatsApp user.

This template uses our Mock Users sample dataset, which can easily be swapped out for your CRM data to build a custom messaging tool for your team.