[Threshold]

pawn Code:

#include <a_samp>

new LastChat[MAX_PLAYERS], ChatWarns[MAX_PLAYERS];

public OnPlayerConnect(playerid)
{
    LastChat[playerid] = 0; // Not really necessary, but you can add it if you want.
    ChatWarns[playerid] = 0; // Reset the chat warnings for new players
    return 1;
}

public OnPlayerText(playerid, text[])
{
    new time = gettime(); // Gets the current time as a unix timestamp (seconds)
    if((time - LastChat[playerid]) <= 3) // If the time between their last message and now is less than 3 seconds
    {
        SendClientMessage(playerid, -1, "[ Don`t Spam ! You can use the chat every 3 seconds ]");
        if(++ChatWarns[playerid] >= 3) Kick(playerid); // Kick player if they have spammed at least 3 times
        return 0; // Stops the message being sent to main chat
    }
    LastChat[playerid] = time; // Saving the time of their new message
    ChatWarns[playerid] = 0; // Reset the chat warnings

    // Rest of your OnPlayerText
    
    return 1;
}