API response to test cases

Hi team,

i am coding for the web service to accommodate the validation of the data being populated by API in the back end.
we have 2 drop list to select the product and duration, based on the combination we get interest values reflected from API call.
we need to validate the interest from the API against the UI displayed texts for the interests.
can you please let us know if we can call the API directly to the test cases for validation.
As API is in OR and we need to test it along the test cases execution, can we call the response