Dropified has a built-in image editor (Photopea) that lets you use advanced features similar to PhotoShop to edit your images directly inside of Dropified.
In order to access this tool, you can simply hover over the product image at the bottom of the Product Edit page in Dropified, then click the Advanced Editor icon.
That will open the image editor directly on that page. Edit your image from there using the advanced features. When you're done, click File > Save.
You can move on to the next image to edit and go through the same process, or if you're done, click the green button at the bottom of the Product Edit page in Dropified to Save the changes.