There is a way to hide photos natively, using private photo album:
You can do it from the original photos app – https://support.apple.com/en-us/HT205891
But this original way has its disadvantages, for example – everyone who knows this way can unhide all of your photos because they are not protected by the passcode or Face ID.
In this tutorial we will take a look at the better and more secure way to hide photos, videos and even apps on your iPhone. First, go ahead and get a free app called Vaulter:
It’s super simple to use, just go ahead and start importing photos and videos, it will automatically ask you if you’d like to delete them after import. Then, turn on passcode protection and select Face ID option if you’d like to use it.
This Private photo vault has all the necessary features to keep your photos safe. Additionally, you get built in browser and apps hiding functionality.