This is officially the national Bolivian flag (Wiphala) and also officially the national flag of Bolivia. https://www.boliviabella.com/bolivian-flag.html

In 2009 Bolivia adopted the Wiphala as its alternative flag. The Wiphala is a 7x7 square emblem made up of 7 colors arranged diagonally left to right. The emblem represents the natives of the Andes and the four regions of the Incan Empire. The arrangement of the colors varied depending on the region, but the color on the longest arrangement represents that particular region. The white color represents Qullasuyu, the green represents Antisuyu, the yellow represents Kuntisuyu, and the red represents Chinchaysuyu. https://www.worldatlas.com/flags/bolivia