Ukrainian Post Office issued a postage stamp on 20 February with a reproduction of a Banksy mural depicting a boy defeating Putin in judo to mark the first anniversary of Russia’s invasion. On 27 February, Banksy confirmed the postage stamp on his Instagram.
You can buy them here: https://postmark.ukrposhta.ua/index.php?route=common/home. The edition is 1.5 mn, and the price is € 4.68 per sheet of six stamps. You can also buy postcards and envelopes with the same motive.