Flask Dropzone Custom Options Seems To Override Everything

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?