Secure boot invalidation/ bios update

hi I'm new to this i have a razer black 15 base model and I'm trying to enable secure boot and update the bios but every time i load onto my laptop it says invalid signature and i would like to know how to fix it without a usb stick because I'm not great with technology and would like help I've tried so many things but it wont help and i really need it gone because its stopping me from doing certain things that i would like to do like play games like valorant because it refuses to open because secure boot is disabled