Hi Felipe,
So, I was using the wrong field in the structure? take a look at the images.
DATA:
t_item LIKE TABLE OF bapimereqitemimp WITH HEADER LINE,
CALL FUNCTION 'BAPI_PR_CREATE'
EXPORTING
prheader = wa_header
prheaderx = wa_headerx
IMPORTING
number = pw_pr_number
TABLES
return = t_return
pritem = t_item
pritemx = t_itemx
praccount = t_praccount
praccountx = t_praccountx
"pritemsource = t_itemsource
"pritemtext = t_itext
EXTENSIONIN = lt_extensionin
EXCEPTIONS
OTHERS = 1.