Change IP Address

I use the Illinois lottery app online and before changing to Tmobile I had no problems with it but since changing now it won’t let me purchase. I emailed the lottery people and they said my problem is that my IP address shows I’m not in Illinois. I checked online and it said I was in St. Louis MO, so I told the site to change my IP so it’s in Makanda, IL now but it still isn’t working. Any ideas?

TIA