The top in the wrap or the "terminator" of the foil at The bottom of the strip next to the outer jacket is usually difficult to see and to locate. If you will find this "terminator," you could nick it with a small Lower with a knife and peel it https://media.wakelet.com/docs/r0CRNcbo0pKmblGKOpRAV?sig=2da888a844c4aba0b1485b7c9fb4ae769ac77261552d26e597f409856a7b305b