You can earn Iberia Avios through credit card purchases on the Iberia Visa Signature card. You can also transfer points from Amex, Bilt, Chase, Marriott Bonvoy, and HSBC to earn Iberia Avios.
Some other ways include flying on Iberia or any of its partners and crediting your flights to Iberia Plus, as well as shopping, booking hotels, making car rental reservations, and much more.