Follow these links for guides on how to find your username for the different types of social media available on 1social.
InstagramYoutube
Google+
Snapchat
Flickr
Messenger
Medium
Steam
Twitch
Paypal
The following are pretty straight forward:
twitterThe following are developer related, I assumed that you know how to find your username:
HackernewsGithub
Keybase
Devpost
Dev.to
Angel
The following do not support any link sharing, instead a username is shown:
Discord (no link)Origin (no link)