PayPal Credit on an Argos order?

[kaykayayres]

Hi! 

I'm trying to complete a payment on Argos for a phone. I have a credit limit for my PayPal already.

I go through the whole process to payment, but there is no option for me to select how many months over I would like to repay?

Im a bit dubious to click pay now when I haven't selected how long?

Any help? I don't want to mess up and end up having to pay a sudden large sum. 

Thankyou

Kayleigh