Conversion tracking pixel - req id code

Summary

Conversion tracking pixel - req id code

Content

I am adding an applicant conversion tracking pixel to the "Thank You" page to track applications through various sources. I have the tracking pixel but I need to add in the requisition ID field and can't figure out how to do that. 

Here's the end of the pixel: "...sourceId=6509&extJobId=MyJobId</script>"

The bolded part of the pixel is supposed to be the requisition ID but I'm not sure how to write that into the code. Can anyone help?