Phaser 3 Arcade physics not getting activated

I think it’s because your scene object is missing from the config. so if your scene is not a class use:

GAME_CONFIG: {
    ...the_rest_of_your_config
    scene: {
        preload: preload,
        create: create,
        update: update
    }
   }

Or:

GAME_CONFIG: {
    ...the_rest_of_your_config
    scene: name_of_your_scene_class_goes_here
   }