“Пропозиції” means “Offers”, this word doesn’t fit the context. “Suggest popular stickers” means “Пропоновувати популярні стікери” and it sounds much better.

“Наліпки” is a definition of “stickers”. The thing is, “Стікери” (“stickers”) has become a loanword and it’s commonly used in Ukraine when we talk about stickers in messengers. “Наліпки” sounds a bit odd in this context. I also checked the Russian version of Telegram and noticed that “Стикеры” (“Stickers”) is used instead of “Наклейки”, and I totally agree with this choice. It is safe to say that we can leave this particular borrowed word because it’s widely used and fits the concept better (what I mean is that we have the same word for “emoji” (“емодзі”) so to make it look consistent I’d suggest leaving it as it is – “Стікери”).