Flask Dropzone Custom Options Seems To Override Everything

[lycheeje11y]

I do not know whether or not this a feature or a bug, but when I include the custom_options value in dropzone.config, like

{{ dropzone.config(custom_options='chunking: true, 
forceChunking: true, chunkSize: 1000000,', 
upload_action=url_for('upload.upload')) }}

Nothing works. No click to upload, no default text no nothing, even when I have this

dropzone.init_app(app)

app.config.update(
    DROPZONE_ALLOWED_FILE_TYPE='default',
    DROPZONE_IN_FORM=True,
    DROPZONE_UPLOAD_ON_CLICK=True,
)

in the right place. I'm assuming that custom options overrides everything. How do I make it only affect the options that it is directly setting?