OKTA multi-factor Authentication + Java + RestAssured: /authorize API call directs me back to login page

I'm trying to perform OKTA authentication via API calls to access one of the apps our company is using. I am able to successfully authenticate through a web browser, so I am attempting to reproduce the same series of API calls executed in the web browser within the RestAssured API in Java.

To do this, we need to invoke a call to {oktaURL}/oauth/v1/token, which takes several form parameters: client_id, redirect_uri, grant_type, code and code_verifier. By generating this token, we can use it to authorize all calls made in the app by adding a header named "Authorization" whose value is "Bearer {token}".

I have almost all of the parameters but I am attempting to generate the "code" parameter using another API call to {oktaURL}/oauth2/v1/authorize, after having successfully generated an "okta_key" parameter for this service through successful authentication.

When the service call {oktaURL}/oauth2/v1/authorize runs in the browser, a response is returned whose "Location" header contains the "code" encoded within the URL:

"{oktaURL}*code=KPgE5DqCNbmqcg4pec_n&state=RKIjvKP9H0X0SZ0TtxBLsEUn647HiPXalMlR65n0f3tgdeURLGobMFZ5Jagdfjxb"

However, when I execute this same service call in RestAssured, I do NOT get this value and get this instead for the Location:

{oktaLoginURL}?fromURI=%2Foauth2%2Fv1%2Fauthorize%2Fredirect%3Fokta_key%3Ds8hTa0bGWkg0aJftmalC2QJ2_ydaJT2-pJKLWnpW5SI

It appears that the attempt to authorize is redirecting me to the login page. Is there any reason why this is happening?