Hi there and welcome
You achieve this through the use of styles on your Chapter headings then updating the TOC. It will then create the headings based on the styles applied throughout the document.
I have an article that will show you how to do this (with pictures) so you can step through how to achieve this.
The article you can follow on my link below
If you have any problems, or would like any additional information or assistance, please do not hesitate to let me know.
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