TinyMCE handle file upload

I am building a React App where a user can create a blog entry with the TinyMCE Editor and he should be able to upload images which works totally fine and I am able to send them to my flask server. I followed the docs at https://www.tinymce.com/docs/advanced/handle-async-image-uploads/ But here's the problem TinyMCE will create a request for each uploaded image but I want to send all images at once to assure I can assign them all to their responding blog entry when storing them. Is there another way I can handle this except using sessions?