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Create a new Autolaunched Flow (No Trigger).
Add a new input variable that will serve as the unique identifier for each record to process. This input variable is necessary for the Batch Job creation.
Click the New Resource button.
Provide the following details:
Resource Type = Variable
API Name = Desired API Name of the input variable
Data Type = Text
Available for input (under the Availability Outside the Flow) = TRUE
Add
thea Get Records element to retrieve the record where an invoice will be generated.
Make sure to provide the exact record that is object of the record.
Filter the records to be processed based on the stored record in the input variable.
Add an Action element to invoke the Invoice API invocable class.
Filter by Type and select Apex Action
Find and select the Invoice API invocable class.
Note: This is a test setup on how to set up Invoice API in Schedule Flow
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