Been answered.Then why is it wrong for Trump to have Ukraine investigate Biden?
https://www.vox.com/policy-and-poli...p-withhold-aid-ukraine-timeline-whistleblower
The Eastern European nation was expecting nearly $400 million in US support — including weapons, training, and advisers — to boost its effort to fight off Russia which invaded the country in 2014.
But by the time Ukrainian President Volodymyr Zelensky got on the now infamous July 25 call with Trump, that aid had yet to be sent. It’s therefore no surprise Zelensky mentioned the assistance to Trump, to which Trump responded he’d like Zelensky to do him a “favor” in return: investigate former Vice President Joe Biden and his son.
It certainly seems like a quid pro quo was pretty clearly implied: You want your aid? Help me dig up dirt on my 2020 political rival.