Subscription Billing / Recurring Billing

I have a small VOIP company. I am building out a system to calculate taxes based on the service line items etc… That’s the easy part. My question is how would I set it up so that the customer could log in and set up automatic payments? I see where I can integrate with the Stripe customer portal to add the credit card and how to make one-off payments for services, but I can’t see specifically how I can do “subscriptions”. I don’t mind if everyone is on the first, id rather that actually, so if I can use a monthly rule to check and see if autopay is set to yes then run the card on file? I am not sure how to go about this and any insight would be helpful.