If you want the full version and license for commercial use,
you can purchase here :

https://fontkong.com/product/amongh-sein/

File Font Version : 

1. Amongh Sein.otf
2. Amongh Sein.ttf
3. Amongh Sein.woff
4. Amongh Sein Italic.otf
5. Amongh Sein Italic.ttf
6. Amongh Sein Italic.woff