Pre-request scripts not working for me

I added some JavaScript in the pre-request script tab for a collection to add some headers but none of them are getting executed.
Here is the text I added:
pm.request.headers.add({key: “Authorization”, value: “Basic xxxxxxxxxx” })

here, xxxx is the key value.

I looked at the console logs and this header is not showing up there, I also added a console.log(“Hello”) that is also not showing up in the logs.

Would really appreciate some help on this.