4

I already wrote my solution. If someone don’t know here it is:

server.lua


TriggerEvent('esx:getSharedObject', function(obj) ESX = obj end)

ESX.RegisterServerCallback('xyz:getGroup', function(source, cb , UserGroup)
    local xPlayer = ESX.GetPlayerFromId(source)
    UserGroup = xPlayer.getGroup()

    cb(UserGroup)
end)

client.js

let ESX = null
emit("esx:getSharedObject", (obj) => ESX = obj)
let groupName

setTick(() => {
        if (IsDisabledControlJustPressed(0, xyz) && GetLastInputMethod(0) === 1) {
            ESX.TriggerServerCallback('xyz:GetGroup', (UserGroup) => {           
                groupName = UserGroup
                
            xyz
            })
        }
});