If you only need to output the text, you don't need to used READ_TEXT like in an ABAP program,
just use the INCLUDE command in SAPScript.
It will read the text and output it to your form.
The Syntax is like this:
/: INCLUDE &T166K-TXNAM& OBJECT &T166K-TDOBJECT& ID &T166K-TDID& LANGUAGE &EKKO-SPRAS&