H1B extension was filed with Texas service center. The paper work was sent by email. Texas Service center issues receipt number starting with IOE.
There is no guideline in USCIS site on where to send H4 I-539 for H1 receipt starting with IOE.
Since H1B extension went to Texas, should the i-539 also go to Texas Dallas address ?
You can either opt to file online or send it to Dallas lockbox.
U.S. Postal Service (USPS):
P.O. Box 660921
Dallas, TX 75266-0921
FedEx, UPS, and DHL deliveries:
Attn: H4 (Box 660921)
2501 S. State Hwy. 121 Business
Lewisville, TX 75067-8003
This seems an oversight on USCIS part. Your H1B was e-filed and so the code is IOE.
You can talk to a live agent via Emma the chatbot and ask.
Based on some forum users experience, USCIS forwards the application to appropriate center if the beneficiary filed at wrong address. So if your H1B is at TSC you can send the paper application to Dallas or simply file the I-539 online.
Or, check with your immigration lawyer as they may know better how to handle this.