I new to API and I am getting below error while running the API query component: Parameter Validation Failure: The value of the attribute could not be accessed: The attribute does not exist. I can successfully create the API query profile

Try passing the post content in as a value via a parameter. This post talks about that scenario: https://matillioncommunity.discourse.group/t/can-you-use-parameters-or-variables-in-the-request-body-of-an-api-query-profile/1319