You can automatically add a conversion to your hosted careers page if you use Indeed Conversion Tracking.
To add your Indeed Conversion Tracker snippet, go to Your Account/Account Details and scroll down to the Customize & Design section and click the Careers Page button
To add your Tracker ID, look for a line that looks like "var indeed_conversion_id = '1234567890';" in your code snippet from Indeed. In this case 1234567890 is your Tracker ID to enter in the Indeed Conversion Tracker ID box.
That's all there is to it!