I have successfully managed to download orders from eBay using the API using PHP, but now I am trying to upload tracking numbers to eBay using the API. Initially I thought uploading order updates such as tracking numbers and downloading orders would follow very similar procedure, but as it turns out I have Large Merchant Services (LMS) to upload tracking numbers.
I found this link which contains PHP samples to LMS: https://ebaydts.com/eBayKBDetails?KBid=1472
Is LMS the only way to upload tracking numbers into eBay? From the search I have been doing it seems that LMS is the only way.