URGENT ..userexit Idoc(inbound ) to mir4 tcode

Am coding in two userexits (ZXM08U25, ZXM08U26 ) of INBOUND Idoc which will update t-code of mir4, and I am testing this using we19.

some field ( field sgtxt of bseg table ) we forgot to send to( they did not give how to pass in functional specs ) ….through IDoc .

Just want to know how the mir4 tcode gets updated by we19 tool..Is it BDC or some direct abap coding UPDATE/MODIFY ?

ERROR is 51 : Field Text is a required field for G/L account IP50 21300010.

Functional specs are not stating that this particular text field … how ever specs stated other texts to pass in internaltable . How can I solve this problem please.