azurerm_lb_nat_pool

resource:
  azurerm_resource_group:
    test:
      name: LoadBalancerRG
      location: 'West US'
  azurerm_public_ip:
    test:
      name: PublicIPForLB
      location: 'West US'
      resource_group_name: '${azurerm_resource_group.test.name}'
      public_ip_address_allocation: static
  azurerm_lb:
    test:
      name: TestLoadBalancer
      location: 'West US'
      resource_group_name: '${azurerm_resource_group.test.name}'
      frontend_ip_configuration:
        name: PublicIPAddress
        public_ip_address_id: '${azurerm_public_ip.test.id}'
  azurerm_lb_nat_pool:
    test:
      location: 'West US'
      resource_group_name: '${azurerm_resource_group.test.name}'
      loadbalancer_id: '${azurerm_lb.test.id}'
      name: 'SampleApplication Pool'
      protocol: Tcp
      frontend_port_start: 80
      frontend_port_end: 81
      backend_port: 8080
      frontend_ip_configuration_name: PublicIPAddress

resource "azurerm_resource_group" "test" {
    name = "LoadBalancerRG"
    location = "West US"
}

resource "azurerm_public_ip" "test" {
    name = "PublicIPForLB"
    location = "West US"
    resource_group_name = "${azurerm_resource_group.test.name}"
    public_ip_address_allocation = "static"
}

resource "azurerm_lb" "test" {
    name = "TestLoadBalancer"
    location = "West US"
    resource_group_name = "${azurerm_resource_group.test.name}"

    frontend_ip_configuration {
      name = "PublicIPAddress"
      public_ip_address_id = "${azurerm_public_ip.test.id}"
    }
}

resource "azurerm_lb_nat_pool" "test" {
  location = "West US"
  resource_group_name = "${azurerm_resource_group.test.name}"
  loadbalancer_id = "${azurerm_lb.test.id}"
  name = "SampleApplication Pool"
  protocol = "Tcp"
  frontend_port_start = 80
  frontend_port_end = 81
  backend_port = 8080
  frontend_ip_configuration_name = "PublicIPAddress"
}