When you create a new subdomain in cPanel it performs a few steps. Without the control panel automating these there is a little more work to do. To create a new subdomain for your droplet and ensure that it is routed correctly by your web server (serving the content in the correct folder) you can follow the following steps:

1. Create a new “A” or “CNAME” record for your subdomain in the DNS section of the control panel (Networking->DNS) or if you are hosting your DNS elsewhere you can create the new record there. [This guide] covers how to use the DO DNS services and the steps needed to create an “A” or “CNAME” record on your domain.

2. Create a new virtualhost/server block on your web server. Now we need to tell our web server what to do if it receives a request for sub.example.org since it was only serving example.org previously. We do this by creating a new Virtualhost (Apache) or Server Block (Nginx) that will tell the web server what to do with a request depending on what name is being requested.

This guide covers setting up virtualhosts in Apache.
This guide covers setting up server blocks in Nginx.

Hello, I could not make my subdomain work with these steps
Hello, I could not make my subdomain work with these steps.
please help