But you have not defined this in code. You are not being asked from where "the data" comes from but from where the object called data is supposed to come from because you haven't defined it in the code you are sharing.
Here you are trying to subsett an onbjec called data but I think you actually want to subset an object called Summary_dates.
If you need more specific help, please provide a proper REPRoducible EXample (reprex) illustrating your issue.