You can find that option while creating or editing a blog post. It is in the editing post right sidebar:
1. Enable: Enable or disable the table of contents.
2. Title: The title of the table of contents.
3. Target Headings: The table of contents is built automatically from all your Target Headings.
4. Bullet Type: 3 types of bullet styles to the table of contents list (none, arrows and ordened numbers)
5. Target Offset Top: Creates a gap in pixels between the browser window top and the respective clicked anchor/target when the scroll ends.
How to exclude one or more “Target Heading” from the Table of Contents?
The class “toc-ignore” should be added as an Additional Class in the heading block you want to exclude.