\paper { tagline = ##f }

\relative c'' {
  \repeat volta 2 {
    g2 c
    d,2 a'
    \once \override Score.RehearsalMark.break-visibility =
      #end-of-line-visible
    \once \override Score.RehearsalMark.self-alignment-X =
      #RIGHT
    \mark "ad lib"
    % In LilyPond 2.23.14 and later, just use this instead of
    % the overrides above:
    % \textEndMark "ad lib"
  }
  \break
  g2 b,
  c1 \bar "||"
}