Extending an existing web application using Codeigniter4

Read the Session class:
https://github.com/codeigniter4/CodeIgni...n.php#L280

Both use PHP session, but the configuration is different.
You need to use the same configuration.
Or use CI Session in both, 
or use native PHP session in both.

Thanks for the reply.

Is there a Config file where I can set this up? I think we should avoid making edits to system files.