Trying for 2 days create firewall rule but cant find the mistake.

I step down step by step and now using an example from hashicorp which also not works.

resource "azurerm_postgresql_flexible_server_firewall_rule" "vpn" {
  for_each = tomap({
    a = "112.234.12.1"
    b = "212.22.111.1",
    c = "22.111.22.1"
  })

  name             = "db-firewall-${each.key}"
  server_id        = azurerm_postgresql_flexible_server.mydb.id
  start_ip_address = each.value
  end_ip_address   = each.value
}

There is no firewall rule create by this code. Whats my bad?