how downlads my photo in my icloud to ipohne

Check to see if you have iCloud Photos turned on

Not sure if you have iCloud Photos set up on your iPhone, iPad, or iPod touch? Here's how to verify:

1. Go to Settings > [your name] > iCloud.
2. Tap Photos.
3. If you need to, tap to turn on iCloud Photos.
4. Download and Keep Originals

If you can't turn on iCloud Photos, you might need to make changes to your storage plan.