This a is tricky subject due to 48's Terms & Condition's... it's something that is considered against their policy... however, if you stay within your usage limit (say on the Don it's 5Gb) you may be ok...
Have you previously used the phone as a hotspot?
You ever had issues with breaching 48s fair usage policy before?
If you have had no problems with Data on 48/able to use the internet... then have a snoop on the Net on tips regarding the matter... iphones are unknown to me-so this is probably the best option to guide you on how to set up a hotspot.
If, however you have had issues connecting to internet, start with checking this link out.
http://community.48months.ie/t5/Need-Help/Apple-iPhones-internet-settings/m-p/3358/highlight/true#M1...http://community.48months.ie/t5/Most-Popular-Questions-Knowledge/iOS-7-Internet-and-MMS-set-up/ta-p/...Can you post back if there is any details you are aware of that would help us answer you better?!
🙂