As a community solar subscriber you pay an up-front or monthly fee directly to your Subscriber Organization (the company or group that manages the community solar system's subscriptions). The Subscriber Organization is then responsible for communicating to the utility company how much electricity your share produces each month. The utility will then apply a credit to the your utility bill.
The credit is equal to the per-kilowatt price that the utility charges, multiplied by the number of kilowatt-hours your portion of the community solar system generates. Effectively, you only pay the utility for the amount of electricity you consume, minus the amount of electricity generated by your community solar share. The total you pay for electricity is the combination of your Subscriber Organization bill and your utility bill.