filestack-react Choose output image format with PickerOverlay

Question

I'm trying to set the output format in "webp" so the files take up less space in the Filestack web. I have been able to do it after the image is loaded, by entering /auto_image/ in the url, but what I need is to change the format before saving the image, and not just to download it. This is part of my code where I think I should set the configuration:

import { PickerOverlay } from 'filestack-react';

<PickerOverlay
    apikey={apiKey}
    onUploadDone={(res: any) => {
        if(imageUrl){
            onHandleUnsavedImages(imageUrl)
        }
        onSetImageUrl(res.filesUploaded[0].url)
    }}
    pickerOptions={{
        onClose: () => {
            handleShowPicker()
        },
        accept: ["image/*"],
    }}
/>

Thanks in advance

I tried in different ways to use "transformOptions", "convert", "output", "format" but I have not had success.