Where is this AT.js code getting the response with the json?

I'm looking at  the obfuscated code from Adobe Target (At.js) . What I'm trying to pin-point is where it initially reads the response with the json structure. I started on this line (Line #4697):

$p = ["/m2/", Rp, "/mbox/json"].join(As),

And started to follow it back but didn't have much luck! Below is a sample response:

https://bankofthewest.tt.omtrdc.net/m2/bankofthewest/mbox/json?mbox=target-global-mbox&mboxSession=0412a0c635b84e0093c135eac04005c1&mboxPC=7c97aeb8c37b4392850e231de01f27ec.28_48&mboxPage=f5e80b627b974d2e83e93b6ef187da86&mboxVersion=1.0.0&mboxCount=1&mboxTime=1503502802144&mboxHost=www.bankofthewest.com&mboxURL=https%3A%2F%2Fwww.bankofthewest.com%2F%23testdtm&mboxReferrer=&mboxXDomain=enabled&browserHeight=226&browserWidth=2304&browserTimeOffset=-420&screenHeight=864&screenWidth=1536&colorDepth=24&mboxMCGVID=14110397794388778776024950675182268582&mboxAAMB=NRX38WO0n5BH8Th-nqAG_A&mboxMCAVID=&mboxMCGLH=9&vst.trk=bankofthewest.d2.sc.omtrdc.net&vst.trks=bankofthewest.d2.sc.omtrdc.net&mboxMCSDID=4FCD89B30AC00AEE-0763922B900740DA&customer=0&Value=

Below is the location of the At.js file (beautified).

https://assets.adobedtm.com/52526302225396ab63a2d854ed0c3ac8d6b71e8e/mbox-contents-c8ee8425853aa6cc8d32135ffc7cfd548c0ce9a1-staging.js

Thanks!