Help!

I posted a job 3 weeks ago and I accepted an application and he completed the job. Now it says:

The applicant has marked the job as finished, you may no longer withdraw. But you need to pay [NAME REMOVED] the agreed amount of $3.50

However, I see absolutely no button where I can pay him. My PayPal e-mail is up to date and so is his.

Any help would be great...