this is what my chat looks like with edited esx_rpchat and chat-theme-civlifechat and the chat resource, dunno if my code works without the two other resources.

RegisterCommand('anontweet', function(source, args, rawCommand)
local playerName = GetPlayerName(source)
local msg = rawCommand:sub(11)
local name = getIdentity(source)
fal = name.firstname .. " " .. name.lastname
TriggerClientEvent('chat:addMessage', -1, {
template = '<div style="padding: 0.5vw; margin: 0.5vw; background-color: rgba(28, 160, 242, 1); border-radius: 3px;"><i class="fab fa-twitter"></i> @Anonymous:<br> {1}</div>',
args = { fal, msg }
})
end, false)