In DesignModeler, the imprint is done with the projection of these lines onto the Surface. Projection is found under the Tools pull-down menu (it looks like you are using the English version). This will slice the face (just over the region of the line) and then you can add a Named Selection to them in DesignModeler or in ANSYS Meshing.
Line bodies aren’t going to help you in Fluent.
You are navigating away from the AIS Discovery experience