how do I transfer photos from Icloud to my iphone11

When Apple ID is signed in Sign in with your Apple ID - Apple Support iPhone , the iCloud is set up Set up iCloud on your iPhone, iPad, or iPod touch - Apple Support and photos box is turned as on Turn iCloud features on or off - Apple Support the photos automatically syncs with iCloud .

You don't need manually to enter www.icloud.com using iPhone Apple ID account credentials from a web browser and download photos Upload and download photos using iCloud.com - Apple Support

See the article Set up and use iCloud Photos - Apple Support