"Please drink more wine."
Translation:Bitte trinkt mehr Wein.
'Trinke' (and 'Trink' too ) is the imperative form for the singular second person while 'Trinkt' is used for the plural second person. So 'Bitte trinke mehr' is used addressing one person while you'd use 'Bitte trinkt mehr' to address a group of people. But, of course, if you talking to a person or a group of people you'd normally address with 'Sie' you'd say 'Bitte trinken Sie mehr.
The word order is wrong. Using those words you could write Bitte trink mehr Wein and it would be correct. The -t at the end of the verb is just used if you're speaking to more than one person. Without it, it only makes sense if you're speaking to one person. So, Duolingo will accept both forms.