How do I link chapters

I am trying to link previos chapters to create branching paths. How do I do it please?

 

Click "Add a new chapter", then look on the right for "Link Chapter (your chapter content will be deleted; create a new chapter and link it instead)".

 

It isnt working just says Link Chapter ID is required

 

After clicking the link, the chapter content gets removed and there is a field for the Chapter Link.
There, you can type in the name of the chapter you want to link to.

 

Thankyou