Craft commerce stripe - Starting subscription without payment fields

Is there a form similar to {{ plan.getGateway().getPaymentFormHtml({})|raw }} for starting a subscription that has a free trial, without taking payment details?

So essentially when the trial is up, I present the user with a form to add the card details.

Or would it just be simpler to create an extra free subscription that merely ends, then present the user with a form to start a different paid subscription? Either way, is there a simple form to start a subscription without payment details? Thanks 🙂