I've just saw the rules and i saw the third-partys are not allowed so uhh i just wanted to ask if bloxstrap is allowed since a litterally use it all the time.

it is not

bro sees that third-party software is not allowed, and then immediately asks if a third-party software is allowed

Bloxstrap is just an fps unlocker but with other cosmetic features I don't get why it isn't allowed if their fps is capped to 60.