Sign a message with the address that has $100k worth of bitcoin.
You have been provided a way to sign the from the account you claimed to have 100k worth of btc and if you cannot do the bolded part then you have just confirmed my earlier statement that newbies like you should not be restricted from posting on certain parts of the forum like this.
I don't think newbies should be restricted from posting on this area just because this troll decided to ask for a $70,000 loan. (lmao!)
Of course Newbie posts are going to be lowest quality on average, but I am quite sure 99% of them will not be useless and/or scams like this one. Generally, newbies should be posting in the "Beginners/Help" section, obviously.