Scale image isn't scaling my image

[Ofnuts]

If you want to crop, close the scaling dialog, this is a different tool

Move the crop handles, they will likely adjust the crop frame to the size you requested

Your canvas is already 1920x1080, if you export the image, it will be automatically cropped to the canvas.

Your canvas is already 1920x1080, you can do "Layer>Layer to image size" to crop the layer to its part that is visible on the canvas.