Make sure you are logged into iCloud on both phones using the same Apple ID. Make sure iCloud is active and in Settings > "Your Name" > iCloud make sure Photos is set to sync. If they are home videos from another source and not taken with the iPhone camera you will need to manually sync them with iTunes.
How do I transfer videos from iPhone 6 to iPhone X
User profile for user: Eonl
Question: how do I transfer videos from iphone 6 to iphone