This is really a question for Theobald Software, makers of the ERPConnect library that the connector leverages. The documentation I've found on their site doesn't indicate anything related to Order By; in fact, they seem to have removed .AddCriteria too in the newest releases (6.1+), indicating to use .WhereClause instead. I don't know which version of ERPConnect you have installed.
It also looks like your code is using a SAP function Z_XTRACT_IS_TABLE, of which several versions can be found online - some supporting ORDERBY as parameter and some that don't.
I don't know enough about SAP to tell you more than that; unless someone else comes in, you might have to open a case with Support.
Btw, next time you'd like to post some code here (which you're welcome to!), please have a look at this post, describing how to do it in the best way.