Why does this variable appear even though I didn't define it

the highlighted variable appear even though I didn’t define it

What the problem?

Maybe you defined it in a link to this app from another app?

Have you tried doing a prject search for that variable to see where it is defined.?

Yes I searched but nothing

I had a similar problem at one time and eventually I stumbled upon it. Do you have a PHP method defined, I always forget to look there