First set the title, and set the first-level title, second-level title and third-level title in the "Start" column, that is, the titles in the style are 1, 2 and 3.

Then, click on the bottom of the first page continuously, select Set Page Format and set page number.

Then, press Ctrl+Enter to create a new blank page, and the cursor stays on the blank page.

Finally, click on the reference, select the directory and directory style, and the directory will be automatically generated ~

Finally, adjust the directory format according to actual needs.

Maybe this dictation is not clear. I suggest to check the contents of "the catalogue is marked in red" on the duplicate checking system. That's where I saw it.