Follow below steps to install OpenSSH server services in Windows Server. Note that in this example, I am using Windows Server 2019.
Step 1 - Type "Apps & features" in Windows search box and then click "Apps & features" in search results.
Step 2 - Click "Manage optional features".
Step 3 - Click "Add a feature".
Step 4 - Find "OpenSSH Server" in the list and then click "Install" button to install "OpenSSH Server", as shown in below image.
Step 5 - Once the installation of "OpenSSH Server" is completed, check whether "OpenSSH Server" is properly installed, and available in the list.
You need to start the OpenSSH SSH services in Windows Server to make the SSH services available to clients. Click the next link to learn how to start the OpenSSH SSH services in Windows Server.