When an image contains pure white (#fff or values RGB 255/255/255) - we refer to this as "blown" or "blown out". There is nothing you can do to alter these pixels to gain lost detail. For example, I've cranked the levels to darken everything, yet here those pixels are...in all their blown glory:

Keeping that in mind, the only thing that you can do is attempt to lessen the impact. You can tone down the white by going to a grey and then tweak the contrast a bit so that the image doesn't look so flat. The below was a quick curves adjustment using Pixlr because I don't have Photoshop on this computer. It's also an uncorrected monitor, but hopefully the point is clear:

The tool that you'll want to use is called "Curves" in most programs. Here's Adobe's Help Article. You'll want to tone down the white to a grey and then bump the contrast by tweaking the curve into an "s" shape. Tweak until you find things acceptable.

Keep in mind that those blown pixels will only ever be white or some value of grey. This may not eliminate what you're calling "glare".

For another take on this, Tetsujin has the photoshop skillz equivalent of a mouse taming a cat and produced the following using "a fairly noisy HDR-style recovery in Ps using curves & dehaze/clarity in PhotoRAW." (Thank you for providing this!)

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For your own photographic advice: if you are ever shooting en environment like this where the subject is very well lit and the rest of the photo isn't, expose for the highlight so that nothing is blown. You can always bring the shadows up in post (at the expense of noise), but you cannot put detail back if that detail is blown.