The Today() function outputs a variable of the type Date, which is then cast into the DateTime variable. When BluePrism casts a date to DateTime, then it sets a time to midnight.
The answer to your problem is that you need to supply the action "Get Reports Data" with the DateTime variable that will be a DateTime of now - 24hours
Example solution to that could be:
Now()-MakeTimeSpan(0, 24, 0, 0)