Pricing
Free while it is in early access.
Now
There is no charge at the moment, and no card is asked for. Everything described on the features page is included.
Later
A price will be set before billing opens. It will be published on this page first, and nobody is charged without agreeing to it.
Billing is built but switched off. When it is on, payment is taken on the payment provider's own pages, so card details never reach this service.