You can do Restrict Access by IP from option panel. You want show your website for specific person. You can add IP and remove IP options available.
Go to => Webriti Coming Soon Pro => Notification Form Settings => Access Settings
Here you can see Access by IP Address. Enter you IP in input field and click on “Add IP Address” button. Now your IP will show in Access IP Address section. Now click on “Save Changes” button. See refer attach screenshot.