How long do you have to wait until Amz PPC starts to generate impressions?

When your PPC campaign is on “delivering,” do you immediately see impressions, or are you supposed to wait a few hours?

I just started my first PPC, and because it’s my first time, I set only “exact” keyword (but they are not uncommon keywords) product campaigns, but I set the bids quite low.

I am not seeing anything thought it has been an hour.

I only see “-” under all metrics.

To be fair it’s not prime time in the US, but still.

Does this mean my bids are too low, or does PPC needs a few hours to kick in?