Hello Farhan,

Sorry, but unfortunately two services used in the Quick Dictionary add-on do not support the Bangla (bn).

Lexicala online dictionary supports 50 languages:
https://www.lexicala.com/resources#fiftylanguages

And Yandex dictionaries supports only 28 languages.

I plan to add other online services that will support more features.

Have a nice weekend!
Oleksandr