Unable insert data into Postgresql database using Entity Framework

Question

I was unable to add user on PostgreSql database on Windows Server 2016. This is my code to add a user:

user = new ApplicationUser { UserName = customer.LookupKey, Guid = customer.Guid };
var password = Guid.NewGuid().ToString().Replace("-", "").Substring(0, 8).ToString();
var result = await _userManager.CreateAsync(user, password);

This code works fine on my localhost, but when me publish to the Windows server 2016, it won't add the data.