Hello, I put an item on sale and now the buyer can't pay because I hadn't enabled the possibility of paying with credit card. What can I do

You can't accept direct credit card payments as you're not a merchant.

Your buyer should have added the credit card to their PayPal account, or paid as a PayPal guest.

If they are unable to pay via eBay checkout now, log into your PayPal account and click on the Request Money tab. Tick the box that says 'goods' and you'll be able to send them a PayPal invoice.

Put the eBay listing title and number in the text both, just for reference. 

Unless you have an acount with the credit card company (Visa or Mastercard) you cannot accept direct Creditcard payments.

Remove this option from your listings.

ONly businesses can use the credit card facilty.

It sound as if you have a wrong email address on their item. Just a slight typing error can cause the problem

If you click on More actions to the right of the item and then Sell similar. Scroll down and check the email address to make sure you have not made an error.

 If it is a viable email address add it to your paypal account.You can add more than one.

 If not the buyer needs to reclaim the payment and pay you again to the correct email address. They can do this through paypal pay for Goods  and send money' tab in PayPal, make sure they select   pay for goods' and enter the item number and seller ID.

 Or you can use the 'request money' tab to send an invoice, selecting 'goods' and enter the item number.   Don't select or accept a 'personal' payment or you will have no Seller Protection.