Join the server and immediately open the player list (F7 or 'P' menu).
The FiveM/Cfx.re team has a strict policy against list manipulation. According to the Cfx.re Support FAQ Fake Players Fivem
The presence of fake players in FiveM has significant consequences for the community. Many players have reported feeling frustrated, annoyed, and even threatened by the actions of fake players. Some have gone so far as to say that the issue has driven them to consider leaving the platform. Join the server and immediately open the player