question about paying for a flight with affirm

i'm planning on booking a flight that is around $1,880, i currently have 1k saved and will have the remaining 880 by my next paycheck in 2 weeks. the airline has affirm as a checkout option, would i be able to select an affirm plan and then just pay 1k upfront and the rest in 2 weeks or do i have to do the monthly payments? i've never used affirm so i'm unsure if it functions similarly to something like klarna in that you can pay whenever you want, haha. i could just wait but i'm sort of worried about the price of the flight going up again before then lol, any answers are appreciated!