How can I get the unique action link ? Or, how can I launch and open

Every record has a unique ID using a!recordLink()
For Actions, you can get the URL of the Action link directly and use it where required.

How can we get the Key for the Action?

when you click on a particular action in the actions tab it will be giving you a link which is unique for each action for example,

forum.appian.com/.../

is routed to ask a Technical question action available in forum,

The current situation is to copy the link and put in constant to create the link in dashboard. Please note that the action links are different for Appian Server even though the action, application and process model are the same.

My question is "How can I use expression rule to get the unique action link in Appian?"

harshav,
That is how can I use expression rule to get the following in your example:

lYBWsQdLlzKy55h829vegxY66Cw-Jrm3JRUBKaX9KAuybyIGc9ray5rCsXcdB5V-zSoOpY8ohznDLI9e2Ie2rINNeE5h9F_FinewY54vGHEGMdJ7lYZ_w

thank you