I was in removal proceedings in Miami Florida and have been ordered for deportation. I have 30 days to appeal...Can I transfer case to Texas after app

Your case is over if only the appeal remains, so there is no case to transfer to Texas.  The appeal is heard in Washington DC.  If, after the appeal is over, and you are successful, one possibility is the case is remanded for further proceedings, in which case you can then ask to transfer the case to Texas.