Switching from Windows 11 to Linux Ubuntu

Hey guys, i have a problem installing Linux on my laptop it turned out to be the Bitlocker is turned on so i need to turn it off but i could not find a way to do so.
So the last three days i had a blue screen issue i could manage to solve it by reseting my laptop

I've tried all the options in the recovery environment but reseting was the last option so i did it and it worked i reset every thing like it's brand new.
Today i open the laptop it's blue screen again i choosed the repair option but did not work and soo many options that failed too so i tried to reset the laptop again but did not work when choosing reset an error came up tellingme i can'tdo it.
so after many researchers I've come to an idea to just install linux and that's it with Microsoft windows so got my flash drive install linux with another laptop and make the flash bootable but linux did not install because off the bitlocker is turned on.
i don't know how to turn it off sonce i can't access the recovery environment no more i can only access the BIOS so guys if you have any idea about this let me now
i think the main cause of blue screen is installing a game from untrusted websites.
so guys if you have any idea to solve this let me nlknow I'll appreciate your help and thank you.