how to do ddt in postman
-- Use collection runner and select external file csv , json
How does Postman know which column is used for which data in csv file ?
postman will look for variable with same name as column name
and set the value of the variable for that column name
for example :
if you have collection variable called zip
and you have column name for your csv file as zip
it will get the value from the zip column of csv file