If you bought a blind box on Douyin but forgot to open it, you can find the unopened blind box in Douyin's personal center page.

You can find the "Gift Box" option in the "My" page and then find the unopened blind box. If you still can't find it, you can try to contact Douyin's customer service team, who will provide you with help and support. Please note that some blind boxes may have an expiration date, so please open them as soon as possible to avoid losing their value.