To withdraw earnings from Ibotta, you need to reach $20. You can withdraw your earnings to a gift card, PayPal or your bank.
On the Home screen in the app, there is another option called Gift Cards (formally called Pay with Ibotta). Here, you can buy gift cards and you earn a percentage back. Normally, it will be debited from a debit card, but there is an option to buy with your earnings. You may need to add a debit card first (under Account, then Gift Cards), but you don't have to use it if you have enough to cover the cost of the gift card.
These options are the only way to get your earnings out of Ibotta.