The effect is as follows:

Effect description:
1. The user enters the @ symbol, an option list appears, and the option list is automatically positioned behind the @ symbol. (The current idea is: dynamically monitor the input character if it is @, and the list box appears at the position where the cursor is hovering.)
2.When the user enters @, the user ignores the choice to continue input, and when the user returns to the position of @ , triggering the display of the list box when clicked after @. (What is this idea, or is there a similar plug-in.)