iOS Question Embedded ObjC code and global session variables

Hello

I'm not sure how b4i works with global variables inside embedded code

I'm trying to implement a NFC Scan alternative that detects ISO15693 tags ( current NFC.scan only detects tags with NDEF info on them)
I need to store a "NFCTagReaderSession" upon detecting the tag, for later use in reads and writes

MY attemps at getting that value to persist have all failed...I'm trying to use a global value
To save the value, but it's not working...someone can tip me in the right direction?

Thanks alot