You can use your phone's mobile data to connect another phone, tablet, or computer to the internet.
Select Settings -> Mobile Network -> Personal Hotspot
Activate the slider next to Allow Others to Join
Select Settings -> Connections -> Mobile Hotspot and Tethering
Activate the slider next to the Mobile Hotspot option.
Select Settings -> Wireless & Networks -> Tethering and mobile hotspot
Activate the slider next to the Personal hotspot option.