If I understand you correctly, you need to open your keys.ini file for LSPDFR and change it there.
It should be this way if you have it on Steam
Windows (D:) > Programfiles (x86) > Steam > steamapps > common > Grand Theft Auto V > lspdfr. There should be a file there named "keys". Open it and scroll down until you see BACKUP_MENU_Key=B. Change it from B to none.
Hope this works out for you!