You may use the Microsoft Windows PowerShell script below to get the service tag of a Dell server, remotely.

This script will automate the process of determining the service tag of a Dell server.
This script will query the server you specificy for it’s service tag.
wmic /user:administrator /node:hostname bios get serialnumber.
Written by Noel Enrique Alvarez on Monday, December 05, 2016.

#Request the domain name
$– USERNAME = Read-Host “What is the username of the administrator account?”

#Request the hostname of the server
$HOSTNAME = Read-Host “What is hostname of the server?”

#Get the service tag
wmic /user:$– USERNAME /node:$HOSTNAME bios get serialnumber

#End of script