How to have my own website for selling SMS?
You can white-label your domain/sub-domain and customize your website as per the themes available.
You can learn how to white-label your website from the link mentioned below:
Also, you can learn to customize your website with the help of the below-mentioned article:
https://msg91.com/help/how-to-create-and-design-website-for-selling-sms
For a video tutorial refer to the link: https://www.youtube.com/watch?v=EPrDYCyBX0g