It’s Thursday, so it’s Q&A day…
If an image is so overexposed that the pixels are completely white, there’s not much you can do. But if the pixels still contain some variation in luminosity, there are many more options.
In the Expert panel first make a duplicate of the background layer. On this copy go to Enhance>Adjust Lighting>Shadows/Highlights. The key setting in this feature is the Lighten Shadows slider. Adjust that until the details in the shadow areas even out. Then use the darken Highlights and Midtone Contrast to address the brighter areas. This will likely create an area that appears a bit over-saturated and strangely sharpened, almost like a faux HDR effect.
If this isn’t the desired effect, use a gradient on a layer mask to hide those regions. Finish the effect by adding a Levels adjustment layer. Pull the sliders inwards to meet the edges of the histogram chart to give additional contrast to the corrected image.