Data API V3 - Issues with post request passing arrays in categories and tags

I am trying to upload a model using the /v3/models POST request from iOS. I am having issues passing categories & tags as a string array. I see that this issue has existed earlier as well, and the example CURL request passes each category as a separate parameter instead of passing them as an array. However, I am using a library for upload requests and this cannot accept duplicate parameter keys (parameters are passed as a unique key value pair dictionary). If I set a single string to a category or tag, it simply works. Any recommendations as to how can this be resolved?

I figured this out eventually. The sketchfab API cannot take arrays and wants each category/tag to be sent separately. You can see this in their swagger UI by inspecting network activity on a sample model post. I ended up adding the parameters one by one (one for each category/tag) into formdata using AFNetworking methods and it worked.