Ukraine issued May 29th a “Frontline” stamp, which appears to honor workers in the battle against COVID-19. The stamp is covers the postage for mailing a letter within Ukraine. The postal agency has also produced a first day cover (shown below) and a maximum card (not shown) for this issue.

You can order the stamp here. The face value appears to be 33¢ U.S., and the stamps come 9 to a pane. Ordering information was not yet available for the FDC or maximum, but they should show up soon in the appropriate section of the online philatelic catalogue.