I'm trying to access the Marvel API at https://gateway.marvel.com/v1/public/. I'm a registered user with public and private keys. However, I'm currently only trying to retrieve a list of characters.
Can you help me identify what might be going wrong?

I finally found the solution!
Within Collections, in the specific collection Settings -> Scripts -> Choose file, you can upload a script to run before the call is made.
Here is the code for the script I needed: