123flamingofan is an account used by Albert in the video, "Roblox BOT actually has conversations with you..." where he joins a game called Flamingo Status Tracker.
About
123flamingofan was created by Albert so he could look at a game called Flamingo Status Tracker which tracks whether Albert's main account, mrflimflam was on Roblox and the most recent badge(s) he achieved. He gives flamingofan 500 robux from The Flamingo Fan Club to buy gamepasses from the game. Flamingofan joins the game and goes into the chat and asks where mrflimflam is, acting like a young fan to which the other people in the chat say they don't know. Albert decides to run an experiment where he stays on flamingofan on his computer and plays a game called RPG Simulator as mrflimflam on his phone and sees how long it will take to update mrflimflam's status and current badge he has. Flamingofan buys a gamepass which tracks supposedly all of Albert's alt accounts, the alt accounts shown are funmanhasfunwoohoo, GeanaSHUTUPSCDFIOJKN, TestAccount00003211, SurvivalGameDev, CraftedLeah and several others.
Albert then abandoned flamingofan soon after.