Comparison of global mbox call (web) vs app call (taken from https://docs.adobe.com/content/help/en/target/using/implement-target/mobile-apps/mobile-custom-user-data.html)
// WEB CALL
http://YOUR-CLIENT-CODE.tt.omtrdc.net/m2/YOUR-CLIENT-CODE/ubox/image?mbox=bk_data_feed&profile.bkCampaignIds=|401309|&profile.bkCategoryIds=|1434650|842410|&profile.bkAudienceNames=|greataudience|anothergreataudience|&mboxDefault=//tags.bkrtx.com/1x1.gif
// APP CALL (FROM ADOBE DOCS)
https://YOUR-CLIENT-CODE.tt.omtrdc.net/m2/YOUR-CLIENT-CODE/ubox/raw?mboxContentType=text2F%plain%3Bcharset%3Dutf-8&t=UNIXTIMESTAMP&mboxDefault=%2Fimages%2Fimages%2Flog.gif&mbox=bk_data_feed&profile.PROFILEPARAMNAME=PROFILEPARAMVALUE&mboxMCAVID=IDFA/ADID