Text (field) frames cannot be inserted directly via the ribbon command Insert | Form object. However, you can insert a text field and convert it into a frame.
To do so, place the mouse cursor at the edge of the text field and choose the ribbon command Convert on the contextual ribbon tab Object that appears. Alternatively: Right-click on the text field to open the context menu and select the entry Convert to object frame.
Tip: Use the ribbon command Insert | Text frame 
to directly insert a text frame. This corresponds to a text field converted into a frame.
A text frame is filled in just like a text field (see previous section): you simply position the text cursor in the field and start typing.
The difference between a text frame and a text field: A text frame, like all other types of frames, has a fixed position on the page. Thus, it does not move when you add or remove body text above it. The normal body text is automatically wrapped around the frame's border lines – it flows "around" the frame.
For information on text fields, see the previous section. For more information on text frames and on the options of the contextual ribbon tab Object, see Text frames.