1) Trump's is lying about Biden in the Ukraine by calling him corrupt in a call for the Ukraine prosecutor to resign to help out Hunter Biden. This has already been debunked. Trump knows it was debunked. He is lying to dupe his feeble minded base i.e. you.. Biden was acting for the good of the US (and other countries) that anted the prosecutor removed so that corruption in the Ukraine could be reduced. Funds were being withheld because it was futile to give Ukraine money if corruption would just take it. It had nothing to sdo with Hunter Biden.
2) It is illegal for a President to ask foreign governments to help them win elections
3) It is illegal to use his office to bribe foreign leaders for election help.
4) It is not illegal to research opponents, work on your campaign, etc when not "on the clock".