Sometimes this will pop up, specifically with a website that has a CA signed by the military, government, or self signed certs. In Google Chrome, at least as of version 92.0.4515.159, you can do this to get around it. Just know, that your session may not be as secure as you’d like, so you better know what you are hitting!
The fix is to left click anywhere on the site page, and then type:
If it worked, the site should reload and get you in. You do not need to press enter, it will automatically take it. There’s no text box, or typing prompt, just type it on the screen after you left click on the page.