How to get my photos back if it wasn’t backed up on iCloud

As suggested, to save important files to external drives, or other cloud service such as google offers,

could be a means to avoid loss; due to errors or misunderstandings of how these technologies work.

• Archive or make copies of the information you store in iCloud - Apple Support

//support.apple.com/en-us/HT204055

• Get help with iCloud Photos - Apple Support

//support.apple.com/en-us/HT204570

• Delete photos on your iPhone, iPad, and iPod touch - Apple Support

//support.apple.com/en-us/HT205856#recover_photos [redirects to section]

Another older feature, not recent ~ may have been used, for a limited 30-day duration:

• My Photo Stream - Apple Support

//support.apple.com/en-us/HT201317

You would have to find your photos from other sources or from your backup of your photos.