Data Fetcher lets you use variables in any request URL, header, parameter or body. Any input with the allows you to use a variable. Before you do this you will need to create the variable in your account.
A variable is a symbolic representation of data that allows you to access a value without having to enter it manually wherever you need it. This can be useful especially if you are using the same values in multiple places. Variables make your requests more flexible and readable, by abstracting some of the detail away. Source: Postman.com
Click to open the settings page.
Click on the account you want to add ther user to. You might need to click first.
Scroll down to Variables.
Enter the variable name and value. Do not use any spaces in the variable name as it can cause issues when using them in URLs.
You will see a message confirming the API key was saved.
In the input for the field you want, click
Click to switch to the variables tab.
Select the variable you want to use.
The input will now have a reference to the variable, which looks like: