How to skip typing a variable into a field if the excel cell is blank

I’m using assign activities to create variables for cells in Excel and then typing each of the variables values into MS Planner. How do I make it so it does not try to type the variable into MS Planner if the excel cell is blank?

not knowing all details about your flow, give a try on:

use an if activity:
Condition: String.IsNullOrWhitespace(YourCellValueVar)
then: do the typing
else: do actions when cell is blank