Answer:
Whenever your thesis statement is visible at the end of the (introductory) paragraph
Step-by-step explanation:
Usually your thesis statement is a combination of the introductory paragraph, or basically just re-iterating what your topic will be about. Some schools don't teach thesis statements the same way as others do. If that is the case, make sure your ending is clear and worded precisely. You are transittioning to the next paragraph, so also make sure your sentences flow into the next paragraph. Hope this helped! :)