Default contact name for SMS

Whenever I receive a text message from some services (namely Google and Blablacar) I see the service name as the sender (for example, if it was in my contacts) instead of the ugly phone number as it appears when the text message comes from others services (Snapchat, Hello Bank).

I don't know if the app from the service needs to be installed on the iPhone for the service name to appear instead of the phone number: I have the BlaBlaCar app installed and (of course) one of the Google apps (Maps), but the sms from Google had to confirm my phone number. as I have created a google account on my computer and not on my phone. Thus, the text message cannot "arrive" from the iOS app.

When I click the Sender's Contact button and then the Info icon, I see the sender's real phone number (for example, 4 66 45 3 for google and 2 52 25 22 27 for blablacar).

I have never added these phone numbers to my contacts myself, and I do not see these "contacts" in my contacts.

I would like to know how this is done, so I can do the same when sending a text message from my server.

Are there some default pre-hidden contacts in iOS?

Is there a field to fill in the application plist file such as "default application phone number" that I haven't seen?

Is this some kind of signup process with Apple so you can associate a phone number with a specific name?

thank