It took a long time for HMD Global to release the first kernel Source Code for some of the Nokia smartphones it released back in 2017. Things have speeded up now since the kernel source code for refreshed Nokia 3 (Nokia 3.1) is already available on Nokia pages. If you are a developer and know how to use those source codes then just head here to download it.
We are still waiting for the bootloader to be unlocked so that Android enthusiasts can start doing some software adjustments and modifications for Nokia phones. HMD promised to do that but there has still not been any word about it, so those enthusiasts still have to train their patience.