There is no line break in a Pronto Hex string.
It is one long line.

Your Browser displays one or more line breaks
because the string is too long to fit without
line breaks. But your browser knows the line
breaks are not really there.

If you highlight and copy as Bruno suggested you
get the string onto the Windows clipboard without
adding any line breaks.

But if you move it through a program such as word,
it will probably turn the displayed line breaks
into real line breaks. Then the Pronto Hex is
no longer valid.