Response: Forbidden

Noob here. Attempting to access the Bar History Data by using the following endpoint within Postman for testing and verification that the endpoint works with the given headers:

https://data.alpaca.markets/v2/stocks/AAPL/bars?APCA-API-KEY-ID=<>&APCA-API-SECRET-KEY=<>&start=2020-01-01T09:30-5:00&end=2020-12-031016:00-5:00&timeframe=1Day

Just signed up. Subscribed to the unlimited data plan. Have not created an individual or business account yet. Just want to test out the API to calculate it’s performance levels and data accuracy before moving forward. Ran this scenario through Postman for testing. Created a new OAuth app for testing. Using the Client ID as the APCA-API-KEY-ID and the Secret Key as the APCA-API-SECRET-KEY. Removed them from the query above for security purposes. Tried recreating a new Secret Key with the same response. What do I need to do to be able do API testing?

Keep getting the following response:
{

"message": "forbidden."

}