I don't think the free tier is real.
Free tier is pretty much a scam. You will send all of your personal details and have a card check, then you'll hear nothing. If you follow up, they will likely ignore you. If you pester them again, you might get a short email saying "Unfortunately, we are unable to resolve this or process the transaction. This is all the information we can provide." (copy+pasted exactly). I've never been rejected for any account and my cards are fine. Good luck trying to get the personal data you provided deleted. That's a process they've designed to be even more frustrating than the sign-up and response. Knowing their CEO, I can only imagine my data has been sold already to fund a certain thing.
(TL;DR) the old adage is true: if something is free, you're the product. Don't try to sign up for the 'free' tier unless you're happy to send your card details and personal data to Oracle with no way to have them deleted.