Hi @signalwarrant
Could you please tell me the version of ACF you are using? If you are using ACF PRO (version 5), please take a look at this page: https://www.advancedcustomfields.com/resources/using-acf_form-to-create-a-new-post/. If you are using ACF free (version 4), please take a look at this page: https://www.advancedcustomfields.com/resources/using-acf_form-to-create-a-new-post/?version=4.
Thanks 🙂