How to remove the modal window on the site with the "back" button on the phone?

Question

css

The site has modal windows that work well on the desktop version, but there is a problem on the mobile version. If a pop-up window is open on the site, and you click on the "Back" button, then the window will not hide (as you would like), and the site will simply close. This is the most inconvenient and problematic.

There was a suggestion to add an empty anchor to the search bar when the window opens. But if you press "Back", then the anchor is removed, the site scrolls up, and the window remains. Maybe there is a way to somehow finish this option? Or are there other solutions?

I would be grateful if you give examples of how this can be implemented. Thank you.