Receipt #IOE?? Which service center is this?

I sent my DACA Renewal packet last week and today I got a text message that says the following:
USCIS: Your case was received. Receipt # IOE Official Receipt Notice (Form I-797) to follow in mail. Msg & Data rates may apply. DO NOT REPLY
Which service center is this IOE from?

The code refers to the USCIS ELIS online processing. I also commented on another thread with the same question, they haven't yet received their receipts. But I told them to check the envelopes when they come in as they have the service center on them

Ok, thank you for the information.