To pass a field from the main flow to a lookup step, “{{record.fieldname}}” is used.
NB: “{{record.fieldname}}” is used to pass the current record before the lookup step. This can also be used if there are more than one control step.
Illustrated in the below image is an example of a SQL Server lookup step where “task_ID” is a field from the main flow that is being used in the lookup step.
How to pass a field from the main flow to a sub-flow or to a control step