why my iphone 7 plus do not have Cellular Data Network?

You appear to not be connected to any cellular network at all. (It says "No Service" in the upper left of both screen shots.)

• Do you have a SIM in the iPhone?
• Are you connected to some cellular network for which this iPhone is authorized?
• Are you able to make/receive voice calls?

https://support.apple.com/en-us/HT201415

Is this something that just started happening? Have you tried removing the SIM card and installing it again? Are you sure this is a SIM that is with the carrier the phone may be locked to? If you have tried these and you are sure that the SIM is with the correct carrier, you need to call your carrier and have them help you out. This is something that Apple is not going to be able to do to get it going, it's got to do with the carrier. I had this before with my carrier and it took a lot of phone calls getting someone who was able to do something. After finally getting someone who was able to remove the phone number from my account and then re-provision the phone at which case it came back up and was working again.