Separate E911 address by phone, not account
I'm trying to get the E911 addresses set for the phones on my account (1 is my son's at college, another is my phone at home) - but there is not a choice to change my son's E911 address on his number, it only shows up for the primary number, which is mine.
He has a Samsung Galaxy S7 Active, I have an iPhone. Does the Samsung phone not support WiFi E911?
How do I get the correct E911 address set per phone?