Hello How can I add more storage to my phone?

You can use iCloud Storage to offload little-used content to iCloud (photos, apps, etc.), and the OS will automatically download/reinstall them any time you need. This is the standard method of freeing up space on your device. There isn't any way to add any additional internal storage.

Check Settings -> Apple ID - iCloud -> Manage Storage to enable this and have the OS automatically offload data.

You can’t add any more storage to a phone. If you need more space, you will need to delete something.