Have you been using iCloud Photos on the old iPhone? If you are using iCloud Photos, the iCloud backup of the iPhone does not include the photos, so restoring the iPhone from the backup cannot bring your photos back. In that case make sure, that you have enabled iCloud Photos on your new iPhone as well, so the iPhone can download the photos from iCloud. Use the same iCloud Apple ID as before.
If you have access to a computer, you can check, if your photos are still in iCloud. Open the web page www.icloud.com in a web browser on a computer and sign in with your AppleID, then open the Photos.app there. Are your photos still in iCloud? Only the Desktop version of this web page will give you access to your iCloud Photos Library.