How to autoload phar files(httpful.phar) in custom component in Joomla 4.3 (php psr4 or psr0 based autoloading)?

I am using a custom component in Joomla and using httpful.phar (https://github.com/nategood/httpful) for REST API. Instead of using the include or require statement, I want to autoload its namespaces and classes. httpful source has Bootstrap.php which does the autoloading. But how can I autoload all the classes and namespaces in similar fashion as other component’s classes and namespaces are autoloaded? I am a little clueless here as this is a phar archive and I can’t directly access its files.

I tried searching over internet and forums but did not get any similar results.