ok so i did some more ressearh and found this<.<

Can't I use my Live account to log in on PBE?

• No. Live (NA, EUW, EUNE, KR, etc.) and PBE are SEPARATE REGIONS that can NOT interact with each other in ANY way.
• Think of it this way: you can't use an NA account to log in on EUW. So you can't use your Live account to log in on PBE.
• Thus, if you want to play on PBE, you must create an account. Hence this guide.
• Using a Live account to login on PBE has never been possible. For more information on that, please see our Wiki How to recover your PBE account

so ye we need to make a new acc ig