How to find out the number to which the SMS came?

Question

SMS

Good afternoon!
I found a phone recently (BQ-some) and there are no contacts, no sim cards, no photos, only sms from the savings like.
So, how can you find out the phone number to which this SMS came? (there is no SIM in the phone!)
And, it also has a Google account - I already tried to write to it 2 times. No one answered.