FTP stands for a File Transfer Protocol, the protocol determining file transfers rules among computers. You must have access to the remote computer you want to work with and provide a valid login and a corresponding password.
-Loginto ISPmanager Control Panel
-Go to FTP Users under the Accounts options in ISP menu
-click ADD to create the new FTP User as you required
-Fill the required details to create the FTP account

Name: Enter the name for the FTP account you want to add. This will also be the FTP user name to get access to this FTP account.
Owner: Account will create under owner or root, or you can create the FTP account based on the account users.
Password: Enter the password to access FTP.
Confirmation: Retype the entered password to assure it has been assigned correctly.
Home directory: Enter FTP account home directory
then click OK, your FTP user has created successfully.

I hope this article will helps you!!
Done!