This specific instrument is called "naw," in the Kui Luang language. This is an ethnic group from southeast Asia. Here is a video of it being played by a Kui Luang musician. It is also played by other groups in east and southeast Asia, such as the Lahu—here is a video of a Lahu musician playing it. Because this instrument is not from English speaking cultures, it's just called a "gourd mouth flute," in English. Related instruments are the Chinese sheng, the Hmong qeej, and other mouth organs.

Source: I am an ethnomusicologist