steampy. Always getting TooManyRequests

Today i started making Discord bot that will track market price of my CS:GO Stickers. Problem is when I trying to fetch market price using steampy I always getting TooManyRequests error.

This fragment of a code.

@client.command()
async def cena(ctx):   
    global steam_client
    f = open('items.json', "r")
    data = json.load(f)
    item_dict = data['items_info']
    for x in item_dict:
        item = x['item']
        quantity = x['quantity']
        cost = x['cost']
        market = steam_client.market.fetch_price(item, game=GameOptions.CS, currency=Currency.EURO)
        print(market)
        if  market == None or market['success'] == False:
            await ctx.send("error") 
            break
        else:      
            lowest = market['lowest_price'].replace("€", "").replace(",", ".")
            ans = f"{item} : **{lowest}€** ||{cost}€ ({quantity})||"
            await ctx.send(ans)
    f.close()
    time.sleep(6)

Here is items.json

{
		"items_info" : [
		{ 
			"item" : "Sticker | Spirit (Holo) | 2020 RMR",
			"quantity" : 1,
			"cost" : 0.50,
			"sellat" : 0.65
		},
		{
			"item" : "Sticker | Virtus.pro (Holo) | 2020 RMR",
			"quantity" : 1,
			"cost" : 0.61,
			"sellat" : 0.90
		},
		{ 
			"item" : "Sticker | FURIA (Holo) | 2020 RMR",
			"quantity" : 2,
			"cost" : 0.48,
			"sellat" : 0.60
		},
		{ 
			"item" : "Sticker | Renegades (Holo) | 2020 RMR",
			"quantity" : 5,
			"cost" : 0.20,
			"sellat" : 0.30
		}
       ]
}

I tried to revoking my Steam API Key it didn't help. I've also tried with another packages like steammarket but it didn't work too. It happends even in first fetch.

EDIT I tried run code today and first time it fetched cost of first two sticker but in sticker three it stopped working at all.

You exceed the rate limit imposed by the Steam API, you gonna have to add a delay in between the request you make.
The best would be to use asyncio.sleep to add delay.

import asyncio

@client.command()
async def cena(ctx):   
    global steam_client
    f = open('items.json', "r")
    data = json.load(f)
    item_dict = data['items_info']
    for x in item_dict:
        item = x['item']
        quantity = x['quantity']
        cost = x['cost']
        market = steam_client.market.fetch_price(item, game=GameOptions.CS, currency=Currency.EURO)
        print(market)
        if  market == None or market['success'] == False:
            await ctx.send("error") 
            break
        else:      
            lowest = market['lowest_price'].replace("€", "").replace(",", ".")
            ans = f"{item} : **{lowest}€** ||{cost}€ ({quantity})||"
            await ctx.send(ans)
        
        # Add a delay between requests
        await asyncio.sleep(5)

    f.close()