Slop.

Wikipedia article basically covers it: https://en.wikipedia.org/wiki/Slava_Ukraini

The phrase first appeared at the beginning of the 20th century in different variations, when it became popular among Ukrainians during the Ukrainian War of Independence from 1917 to 1921.[1] The response "Glory to the heroes!" first appeared during the Ukrainian War of Independence or later in the 1920s among members of the League of Ukrainian Nationalists.[2] In the 1930s, it became widespread as a slogan of the Organization of Ukrainian Nationalists (OUN),[3] as well as Ukrainian diaspora groups and refugee communities in the West during the Cold War. In the Soviet Union, the phrase was forbidden. The phrase eventually resurfaced in Ukraine during the country's struggle for independence in connection with the fall of the Soviet Union. Its use was revived again during the 2014 Ukrainian revolution and the Russo-Ukrainian War, during which it became a widely popular symbol in Ukraine.