Take the number of cards in the subject you have not learned yet, divide by the number of days you have, and subtract two or three days from the bottom of that sum so the last cards get seen more than once.
A worked version. The prep bar on your exam reads 34 of 96 learned, and the exam is in fourteen days. That leaves 62 cards to get through. Working to eleven days rather than fourteen gives you about six new cards a day, plus whatever reviews come due, and three days at the end where nothing is new and everything gets consolidated.
A card seen once is not learned. The first correct answer buys you a day, the second about three. A card you meet for the first time on the evening before the exam has had no chance to survive a gap, and it is the first thing to go under pressure.
Front-load the new material and leave the end clear.
There is no daily cap and no new-cards-per-day setting. Every due card is shown. This puts the pacing decision on you, and nothing stops you adding ninety cards the night before and regretting it.
The countdown tells you when. The prep bar tells you whether to worry. When those two disagree, the prep bar is usually the one to act on.
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