public Gift(playerid) 
{ 
    GiftPlayer(playerid, 1); 
    gifttimer[playerid] = 0; 
    gettinggift[playerid] = 0; 
    giftsenabled = 1;//try this
    return 1; 
}  

and here
...
if(IsPlayerInRangeOfPoint(playerid, 3.0, x, y, z)) 
            { 
                gettinggift[playerid] = 1; 
                giftsenabled = 0;/////////////////////
                format(string, sizeof(string), "* %s reaches inside the box with their eyes closed and grabs something.", PlayerName(playerid)); 
                ProxDetector(30.0, playerid, string, PURPLE, PURPLE, PURPLE, PURPLE, PURPLE); 
                SetTimerEx("Gift", 1000, false, "i", playerid); 
                return 1; 
            } 
...

if(giftsenabled) // If this variable is 1 the code will continue and you will recieve gift, so it means that you must set this variable on 0 if you want to skip this process for some time
        { 
            if(gifttimer[playerid]) return SendClientMessage(playerid, GREY, "You must wait an hour before getting another gift."); 
            new Float:x, Float:y, Float:z; 
            GetDynamicObjectPos(dynamicgift, x, y, z); 
            if(gettinggift[playerid]) return 1; 
            if(IsPlayerInRangeOfPoint(playerid, 3.0, x, y, z)) 
            { 
                //When is everything correct, then you will get your gift
                giftsenabled = 0;//So you can block this part of code for some time
                gettinggift[playerid] = 1; 

                format(string, sizeof(string), "* %s reaches inside the box with their eyes closed and grabs something.", PlayerName(playerid)); 
                ProxDetector(30.0, playerid, string, PURPLE, PURPLE, PURPLE, PURPLE, PURPLE); 
                SetTimerEx("Gift", 1000, false, "i", playerid); //you will block it for an hour (3600000) and then
                return 1; 
            } 
            else 
            { 
                SendClientMessage(playerid, GREY, "You are not near the gift box."); 
                return 1; 
               } 
...

public Gift(playerid) //this will be processed every 1 hour
{ 
    GiftPlayer(playerid, 1); 
    gifttimer[playerid] = 0; 
    gettinggift[playerid] = 0; 
    giftsenabled = 1;//and there you will enable the /getgift command
    return 1; 
}