Bangla Sentiment Classification Datasets
Multiple sentiment classification datasets for Bengali, which can also be used for training LMs. The Datasets are the following:

ABSA_datasets -- This dataset has developed to per­form aspect ­based sentiment analysis task in Bangla.
License: CC BY 4.0

SAIL_data -- This dataset, consists of tweet posts, has developed in the Shared task on Sentiment Analysis in Indian Languages (SAIL) 2015. [2]
License: Non-profit

multichannel_bsentiment -- This data was collected from several newspapers, TV news, books, blogs, and social me­dia.
License: NA (N.B.: We have the permission to share this dataset.)

youtube_sentiment -- This dataset was devel­oped by extracting comments from various YouTube videos.
License: NA
https://github.com/banglanlp/bnlp-resources/tree/main/sentiment
Yes - it has a direct download link or links
https://github.com/banglanlp/bnlp-resources/tree/main/sentiment
Yes
The work is licensed under https://creativecommons.org/licenses/by-nc/4.0/. However, for each dataset, please see the license information associated with it. Any private dataset can be accessed by contacting with the respective authors.
research use
cc-by-4.0: Creative Commons Attribution 4.0 International