Intercourse 3 days before IUI

Caroline

So I just got a call from my dr and said that my husband and I have to have intercourse tonight and then trigger tomorrow and come in Friday morning for our first

<a href="https://glowing.com/glow-fertility-program">IUI</a>.. I work until 10 pm tonignt and live 35 mins away from home and we're getting snow tonight so it'll be a longer drive home and my husband has to get up at 2 am for work.. guess my question is how important is it to have intercourse tonight? Is it a must?