Deserializing JSON back to Django Model (File Error)

[Johnson Kuang]

I have a REST api that serializes a filefield. On the api, it displays the
absolute url of the file which works. Example: "pdf_file": "
https://makeabilitylab-test.cs.washington.edu/media/publications/Evaluating_Angular_Accuracy_of_Wrist-based_Haptic_Directional_Guidance_for_Hand_Movement_nIxCCJA.pdf
<http://makeabilitylab-test.cs.washington.edu/media/publications/Evaluating_Angular_Accuracy_of_Wrist-based_Haptic_Directional_Guidance_for_Hand_Movement_nIxCCJA.pdf>
.

However, when attempting to deserialize the JSON objects back into Django
model objects, it raises this error: {'pdf_file': [ErrorDetail(string='The
submitted data was not a file. Check the encoding type on the form.',
code='invalid')]}. What procedure do I have to go through to process these
urls back into the files that my filefield requires?