It’s actually somewhat complicated to set up, so below is an example… The extra quote marks around the text string is to accommodate text with spaces in it - otherwise you will only get the first word. The order in which you pass the command line arguments is critical.
import rhinoscriptsyntax as rs
text_string=rs.GetString("Text to insert?")
pt=rs.GetPoint("Text insert point?")
ht=rs.GetReal("Text height?")
opts="GroupOutput=No FontName=Arial Italic=No Bold=No Height="+ str(ht)
opts+=" Output=Curves AllowOpenCurves=No LowerCaseAsSmallCaps=No AddSpacing=No "
rs.Command("_-TextObject " + opts + '"'+text_string+'"' + " " + str(pt) )