Hi @Karam_Abulawii,
You want the values for given keys in in_TransactionItem.SpecificContent.
You can use assign or multi-assign activity
YourVariableForFirstName
= in_TransactionItem.SpecificContent("FirstName").ToString
YourVariableForLastName
= in_TransactionItem.SpecificContent("LastName").ToString
and further.
This question is quite similar to the ones asked here