Windows 10 administrator issues

I only have one account on my windows 10 computer and recently set up a PIN to prevent our teen using the computer after being grounded. Now every time I try to do anything (make changes or install software) a window pops up asking "To continue, type an administrator password, and then click yes".

But, there is no option to enter a password (and I don't know the password anyway) and unable to click yes. FRUSTRATED. Please help!!!!!!