Install Nesbox emulator in Wordpress 2

Question

I am in doubt about how the code was used to create the shortcode and how HTML is generated. I followed all the development in the post with doubt about how Install Nesbox emulator in Wordpress, including the chat conversation. But there are no codes and there are conclusions implied. So, someone could give me a help with this, it’s just now.

• I can run the emulator on a separate page pure HTML and created the plugin as example, but when active the plugin gives a fatal error in Wordpress:

"Warning: session_start(): Cannot send Session cache Limiter -
headers already sent (output Started at
/home/tipsg762/public_html/snesoline/wp-content/plugins/arcadetom/arcadetom.php:36) in /home/tipsg762/public_html/snesoline/wp-content/themes/arcade-Pulse/functions.php on line 1438"

Thanks in advance!