What to do if MacBook Pro 2017 uses more wattage than the charger can give?
You should check the power of your charger and then check the power required for your MacBook Pro. I think you need a 87 Watt charger but smaller chargers will work although they may exhibit the problem you see. You can check the required charger and cables for  your computer here.

If your charger is less the 87 Watts your best options are to go back to wherever you bought the computer and explain your problem or buy a new charger from Apple.