API: High Frequency Alert. More than 20 pushes within 6 hours

I am receiving the following error in my push notifications panel “API: High Frequency Alert. More than 20 pushes within 6 hours.”

As per API documentation

API Rate Limit (API Rate Limit - Webpushr)

All API requests are limited to 1 request per second at this time.

Question 1: Is there any difference between requests per second and pushes?
Question 2: Please clarify what is Webpushr’s Hourly or per/ minute policy limit for sending push notifications?
Question 3: Is this policy limit same for all subscriptions/ packages.