Big Congratulations!! You're well on yoyr way... Amex tends to accept thin profiles with open arms.
Yes, that's the POT (pay over time) feature. You would need to set it up when charges over $100 post to your account. I've never actually used it as I don't have one of the charge cards...(my current spend doesn't justify the annual fee), but my understanding is it allows you to set up a plan to payoff the purchases you add to the POT with a set monthly paynent amount & apr over x number of months. All other charges not included in the POT would need to be paid in full by the due date (as charge cards have historically worked).
If you start a new thread asking for more details about how POT works, you'll get some more solid answers from folks here that have 1st hand experience.
Again, congrats & enjoy - welcome to the Amex fam!!