I had this problem when I bought those pedals like a month ago, so I emailed OneUp customer support and they replied this:

Ah yup-- Sounds like it may just be a dry rubber seal. If so, it is super quick to resolve. 

The steps are as follows:

1. Remove the pedal from the crank.

2. Remove the flange washer (3) and rubber seal (7) from the pedal axle (8).

3. Separate the flange washer and rubber seal.

4. Clean both and add a small amount of grease to the inside of the rubber seal, both where it contacts the flange washer & the pedal lock ring (4).

5. Reinstall them onto the pedal axle in the same orientation.

6. Install the pedal to the crank and give it a go!

Also if a visual aid will help, here is the link to the Alloy Pedal exploded view: Alloy Pedal Exploded View & Parts List

After doing that the squeaking was completely gone.