SVG format itself doesn’t support angular gradients (this is not a Figma issue), so your only option would be to rasterize it.

Oh… ok thanks for your response 🙂

@Gleb What are the keyboard shortcuts to pixelate only this element of my Figma file?

Select the layer, use the quick actions search → rasterize

Or if you need higher resolution, you might want to export it as PNG first at desired resolution and then re-import into Figma.