Robbie plans to retire in $20$ years and has just established a personal retirement account where the annual return rate is $6\%.$ If at the end of every month in the coming $20$ years, Robbie will deposit $$500$ in the retirement account, what$$s the monthly amount $($at the end of each month$)$ he can withdraw from this retirement account in the $10$ years after retirement $($Robbie will have a zero balance after the last withdrawal$)?$