This is the Q&A layout and that button name is not .

Also, user cannot see button if the topic/question is opened by himself, there is no idea to answer own question. User cannot see this button in own topic if the "Can answer own question" permission is disabled for his forum access. You can edit Forum Accesses in Dashboard > Forums > Settings > Forum Accesses admin page.

There are many options in the Dashboard > Forums > Settings > Topics & Posts admin page for the Q&A layout topics:

• Q&A Layout - Comment Form Type
• Q&A Layout - Display Answer Editor
• Q&A Layout - Number of Answers per Page
• Q&A Layout - Number of Comments per item in page load
• Q&A Layout - First Post Reply Button

You can try to switch the read marked options. 

Could you please show me on a screenshot where you're searching the reply button. Are you loggedin?

If you have a cache plugin please make sure the forum page is excluded from your cache plugin, more information in this topic: https://wpforo.com/community/faq/wpforo-and-cache-plugins/

Thanks.