How do I record and charge costs to a restricted fund for a charity? I'm using quickbooks online but it doesn't have the classes feature. Any help would be appreciated.

We are a charity not for profit and still finding my feet with quickbooks online. We have received a restricted fund in our bank account and I don't know how to record the restricted fund and then charge the appropriate costs relating to this restricted fund. For some reason I can't find the option to select the classes feature on my quickbooks online account. Is there another way to record and monitor this restricted fund without the classes facitliy?