Passing external $_SESSION values into CakePHP framework [CakePHP 4.x]

Link to my question on Stackoverflow

I am hoping to pass an external Session value, which is accessible outside, into the Cakephp framework. In a controller method where I need the value, I did session_start(); and tried to echo the value but it returned an empty []. Please refer to the above link for details.

It would be appreciated it I could be advised…