How to gradient fill drawn shapes?

I researched quite a bit already, and all that I found was how to apply gradients to text generated with Pillow. However, I wanted to know how can I apply a gradient instead of a regular single color fill to a drawn shape (specifically a polygon).

image = Image.new('RGBA', (50, 50))
draw = ImageDraw.Draw(image)
draw.polygon([10, 10, 20, 40, 40, 20], fill=(255, 50, 210), outline=None)

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