I want to insert add2any script

I was hoping someone could help me use add2any script on my site?  I need to add the script sitewide before the /body tag.  Can someone give me a heads up on how to do this or point me to a post that will explain it (recently).  I have searched but I only find really old ways or plugins that are no longer supported. I do not want to remove the Powered by Elgg, I just wan to add the script.