How to access profile in current iOS iPhone 6s

Hi!

I recently used a travel sim while overseas. When I came home (Australia; network Telstra) I switched SIM cards back, but it comes up with a message that says “Could not activate mobile data network. You are not subscribed to a mobile data service“. I’ve restarted my phone and also done a cold restart. I’ve double checked mobile data is in and data roaming on. I’ve looked online and it mentions the other sim may have created a new profile in my phone and to go to settings > general > profiles or settings > general > device management, to delete the profile for the travel sim, but these locations don’t exist on the current iOS. Can anybody help? I’ve also gone into settings > general > reset and hit “reset network settings” and that didn’t help either! I could try to restore from backup but I’m concerned about losing other new information like the 1000 photos I took while travelling, etc.

Any help would be greatly appreciated.

Regards,

Carrie