The prepaid unlimited plan doesn't have the mobile hotspot feature included so you will need to switch to one of the tiered prepaid monthly plans that include a mobile hotspot feature or switch your account to postpaid. For the postpaid plans you need to choose either the Play More Unlimited Plan or higher depending on your needs and budget.

You can compare the features on the website. https://www.verizonwireless.com/plans/unlimited/