You can install it easily like below (I've tried it in Fedora 42),

1. git clone https://github.com/sarim/ibus-avro.git

2. cd ibus-avro

3. sudo dnf install ibus-libs

4. sudo dnf group install development-tools

5. aclocal && autoconf && automake --add-missing

6. ./configure --prefix=/usr

7. sudo make install

Then just Press super (windows) key and search for Inuput method selector, then scroll below and click ... button for other language. Now you can search for avro or just select Bengali and select iavro.