How to resize/compress or Set default height width / stylesheet classes of Images Upload by django Ckeditor

I'm Using Django-Ckeditor for RichTextUploadField, However, some images are pretty large and I need to resize/compress before sending it to server

or If i can set default width and height or Stylesheet classes

I tried this but no luck:

CKEDITOR_CONFIGS = {
'default': {
    'stylesSet': [
        {
            'name': 'Image-Fluid',
            'element': 'img',
            'attributes': {'class': 'img-fluid'},
        },
    ],
},

}

Need your help community. Any Idea How to make this possible. My CKeditor config: gist