Action Parameters can be created in this way:-


Right-Click on Action in Keyword View
Click on Action Properties
Select Parameters Tab

***********Action input parameters*********
Click on "+" and add  the input Variables with their 
respective datatype and their Values

***********Action output parameters*********
Click on "+" and add  the output Variables(o/p Var name)  
with their respective datatype
Note- Here there is no Default Value tab 

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Once you have created Action Output Parameters
write in the Expert View of the same action
Parameter("o/p Var name")="pass"(you can give any values)

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and then yopucan call this action in any other actions 
within same or different test