How to Send Invitations to Your Plus Ones

I never got a formal invitation for my plus ones yeah yeah I guess they could always ask the original guest like what's your plus ones info so I can send them a letter or whatever but maybe you also like got one because of like you were the plus one of someone that is very close to. It was an interesting thing for me for like this past wedding where I went with my parents right but I also know my family friend and we've been friends since we were pretty young like they were church and stuffso then I was like should I gift with my parents or should I like gift separately? So I was like I'll just gift us separately, which kind of makes sense in terms of