ringer

Phone

"Bing my ringer",
To text someone on their phone

Person A: "I have to shower brb"
Person B: "Aight we'll get litty afterwards then famio"
Person B: "bing my ringer xd"

"You want my digits? Bing my ringer!"
In this scenario, the person doesn't want to give you their number & tells you to text a non-existent phone number (which could actually be theirs). You can't text (bing) their phone (ringer) without their number (digits), essentially rejecting you in one phrase.