Not sure if this has been covered but I’m creating a simple form in Writer that can print lines so that the form can be printed out and filled in manually. But it also needs to be able to be typed on the line without increasing its length. Sorry if this is garbled but I can’t find an answer elsewhere, probably because I’m using the wrong keywords.
A line will not work. From the View menu>Toolbars>Form Controls. Use the appropriate controls. Text fields can be formatted so that only at the bottom is a line.
Have a look at the documentaion: English documentation | LibreOffice Documentation - Your documentation for LibreOffice
Further explanations can be found here, unfortunately in German. For video, you can use settings to change the subtitle, e.g. English, select.