Unlike English, there is no need to use the plural form of sticker (بزچسب)

almost no one saying برچسب ها to the stickers in Iran. all call it stickers. so the استیکرها is correct. also the verb افزودن is not being used in conversation these days, just in some books! so we can update it with اضافه کردن . or even better, change it in a way that i did. " i want these stickers!