How record line in audio on iPhone with lightning jack?
You need a Lightning audio interface. There's a lot of different products in various price ranges from a number of makers. Note that there are some that are targetted at specific instruments such as guitar or bass, or microphones - and some have multiple types of inputs.

You could for example take a look at the Line 6 Sonic Port audio interface for Lightning or similar.

If you want something for 3.5mm minijack, you could instead look at the Tascam iXZ Microphone and Audio Interface for iOS (approx. 60$). 

Any assorted music store, or online vendors such as Amazon, has multiple types of these products. Some cheaper than the these, some much more expensive.