Include text to indicate the action of clicking the "Add Topics"

Include text to indicate the action of clicking the "Add Topics" button next to the field where the text was entered.
On the "Add Topics" page, the field where the topic needs to be entered requires the next action to be clicking the button next to the text field. However, there is a lack of indication prompting the user to take this action. If the user does not perform this step, the topic will not be added, even if it is written in the text field.