Field code
issue?.links[0]?.type?.inward
Links are stored in lists. Documentation on how to work with lists can be found here.
You can access the whole link type by issue?.links[0].type
which returns an Issue link type object, issue?.links
will return a list of objects.
If you need the overall name for this type, please use issue?.links[0]?.type?.name
. The result will be "Duplicates".