Hard return to end a paragraph

I am having a formatting problem. I use a blank line to represent an end of paragraph. When I hit return I go to the next line so I hit enter twice. When I cut and paste to an online site their software automatically adds an end-of-paragraph for every hard return.

How can I use a single hard return to create an end-of-paragraph.
I thought this would be an easy one but I can’t find the answer in help.

You may need to contact the web page administrator…

If you need to preserve original LibreOffice document then I suggest to do the following work-around:

  1. Save your document after you finished writing (you have 2-enter keys for paragraph).
  2. Edit | Find & Replace (or hit CTRL+H).
  3. In “Search for” type in: $
  4. Leave “Replace with” input box empty.
  5. Click on More Options.
  6. Check Regular Expression.
  7. Click on Replace All. This will delete one single “enter” character in every paragraph. Copy content to web page.
  8. To get back original document in LibreOffice. Close the document without saving and open in step-1 saved document.

    You may also try to record a macro to do the task.