Outside of Europe and European-derived forms, harmony is very rare.
It's not rare, but it has different forms than western music. Maybe the most common form is pedal, which can be heard in this Tuvan form: https://www.youtube.com/watch?v=1rmo3fKeveo
Almost any time there are musical instruments accompanying singing, you'll get some form of harmony, like with this Japanese shamisen music: https://youtu.be/_k0wyAIkPhM?t=916
Pedal tones aren't really the same as Western harmony. You can't transition from one key to another. The pedal is more like a consistent pitch reference. Likewise, countermelodies aren't necessarily harmony, although harmony is technically countermelody.
It's not rare, but it has different forms than western music. Maybe the most common form is pedal, which can be heard in this Tuvan form: https://www.youtube.com/watch?v=1rmo3fKeveo
Almost any time there are musical instruments accompanying singing, you'll get some form of harmony, like with this Japanese shamisen music: https://youtu.be/_k0wyAIkPhM?t=916
Native Australians have harmony that I would call pedal, too: https://www.youtube.com/watch?v=V1pDPuetPdg