In many cases, FANBOX is a place where creators and fans can interact in numerous different ways.
For example, you can solicit requests from your supporters, post surveys, or make a Discord server limited to your supporters. On FANBOX, you don't have to post works, and you don't have to feel pressured to please fans.
To post a survey on FANBOX, you can use Google Forms. All you have to do is embed the URL for the form you created in your post to FANBOX.
Reference link ①: I want to embed an image or file in the text of the post
Reference link ②: You can embed a Google Form in the text of the post