Mohd please clarify, is the credential in the Blueprism Credential Store or in a different Database all it's own?
if it's in the credential store you can use the Blueprism - Internal object 'Internal - Credentials' and the action 'Get' just supply it the name of the credential from the Blueprism credential store.
If the credential is in another database altogether you're going to need to perform an SQL query to retrieve it from the Database and store it into the Blueprism environment via a code stage.