Gettin the pfx for an app to use in Mailgun and pa

问题:

I'm trying to use mailgun to send verification emails and recover passwords from Parse Server (working on AWS) and it's been a real pain since I don't know anything about node.js. I'm using this adapter and following this post but I'm having problems to fill this info:

push: {
    ios: [
      {
        pfx: 'FILE.p12', // Dev PFX or P12
        bundleId: 'BUNDLE',
        production: false // Dev
      },
      {
        pfx: 'FILE.p12', // Prod PFX or P12
        bundleId: 'BUNDLE',  
        production: true // Prod
      }
    ]
  },

I understand that the pfx is a keychain file but I don't understand how to find the one I'm using for my app, and I guess Dev is the developer and Prod is my specific app, so is it the file that I get when I try to upload to the app store or what file?, also de bundeID I understand that is the com.name.appname, but it asks for two, so what is the other one? A little help wpould be much appreciated, I've been trying to set this up for the past 3 days and can't find a way to do it. Thanks!