If you'd like your customers to not have the option of saving their checkout information, you can set your store to allow Guests only. Note that a subscription product type will require the customer to save a password since you need to save the payment information to process recurring payments automatically.

Here's how:

1. Go to your Foxy administration templates configuration page here
2. Scroll to “Customize the checkout user type (account vs. guest)” and check the box to reveal your options
3. Under “checkout type” select “Allow guests only”
4. Scroll down and click “Update” to save

Past saved customers will no longer be prompted to enter a password and new customers will not be prompted to save a password.