Getting throttling Error while trying to hit the GetItems PA API

Earlier i was able to get the data using the endpoint on PA API but from last few weeks i am not able to access any of the three APIs for my end, and it is providing me with the error statement i.e "The request was denied due to request throttling. Please verify the number of requests made per second to the Amazon Product Advertising API." As i researched for the same i assume there might be one of the two reasons for the same i.e Multiple request in a single minute or my account is not able to generate enough revenue. So can you please help me with the exact reason due to which i am not able to access the APIs and get the data. Please also help the steps by which i can get this error resolved and get the data from Amazon Affiliates PA API from my end if any.