Thank you, @piggz and @nephros. I could install emmc.img. However, now I am having a small issue. On boot every time it ask for if I want to encrypt or not. If an I give “yes” or “no”, it does not matter, it says an error - Failed to setup the filesystem. This suggests and error in device adaptation. Please contact the porter of the device.
If I enable developer options and say Quit, it goes to login and works fine. Not sure if it is ok or do I need to do anything from my side.
@eson, I tried searching in Jolla and Chum on my Pinephone Pro. I do remember seeing the client when I was using Aquafish sometime back. Maybe I missed some settings here.
It is working now. It seems that first-boot.sh in overlay folder is not running properly. Downloading and running that file manually removed the issue of asking encryption everytime.