Write to Data Store Entity Invalid Cast: Cannot cast from type 'NL_LoanActions' to type 'Data Store Entity' (Data Inputs)

It likely means that the value you provided for the Data Store Entity is a variable. However, that input should contain a reference to the entity you want to write to (usually referenced via a constant). Then, you should add an additional input that includes the data that you'd like to write. Take a look at this screenshot for an example: docs.appian.com/.../Write_to_Data_Store_Entity_Smart_Service.html

In datastore entity configuration you have to provide Datatype name instead of the variable name.

In the below Snapshot, ET_AccountDetails is my CDT. I create another input variable which i have to insert into Database. Make sure the CDT which you provide will be the same type for second variable(account details in my case). in that second variable, Map your process variable to insert the data into DB.

Note: If you have multiple rows to insert then please select multiple checkbox in the second parameter.