Pronunciation is 'kuai4 yi4dianr3.' Bit tricky but the last two characters are pronounced as one syllable: 'dyair' (sorta). Altogether 'yidianr' is used after an adjective to mean, roughly, 'a little more' of that adjective. At least to my understanding, I'm by no means fluent in this language haha.
As I understand, 一点儿 softens the tone of the command and makes the sentence more polite
I said "quickly!" and I got it wrong, then Duolingo corrected me to "More quickly" which sounds awkward af. Nobody whom I know who can speak English has ever said something like that, ever! Not even my 12354634624 English teachers I've studied with since the beginning of time.