How do I use Placeholders in P# Scripts?

Placeholders in P# scripts allow users to change values as needed each time they run the report. String and Double values can also have a default value that's already pre-filled when the Placeholders modal pops up

For certain items, placeholders have been established: Entity, String, Double, Signal.

After running the script, the user can see the defaults.

The user can select units.  The date always defaults to the current day.

After hitting "Apply and Run" it will show the default value in the table.  It can be updated at a later date.