Service Portal does not have Distribution Lists added to the field "Watch List"

Service Portal doesn't support to add distribution list to the field "Watch List"

Service Portal doesn't support to add PDL to the field "Watch List"  as it comes with  out of the box settings.

A good link for reference could be - https://www.servicenowelite.com/blog/2017/6/1/service-portal-watchlist-widget

This is a custom requirement to add distribution list in the watch list on a service portal