I emailed support after having issues loading/finding my "stickers". Same issues others have mentioned. Stickers are different than emojis or keyboard languages. I learned this after contacting the developer. They sent me a video that, while not a step by step explanation, it showed enough for me to open the stickers up. Now I see a bunch of stickers I can use I did not know I had.
Please contact the web developers before giving poor reviews. It may take a bit longer, but they do want you happy.