Using Bengali script in linux version of LibreOffile in Chromebook

I am using a linux version of Libreoffice in chromebook. I have set the keyboard layout to Bengali. Under Tools>Option>Language Settings> Languages I have set The Complex text layout to Default-Bangla(Bangladesh).

I have also selected the “Noto Sans Bengali” font. But I am unable to type in Bengali script.

Your question has nothing to do with LibreOffice. Consult your operating system manual. In Linux, you might want to try ibus.