documentclass[10pt]{article}

usepackage{graphicx}
usepackage{colortbl}
usepackage[table]{xcolor}
usepackage[many]{tcolorbox}

usepackage{XCharter}
usepackage[T1]{fontenc}

newtcolorbox{learng}{
  breakable,
  enhanced,
  arc=0pt,
  outer arc=0pt,
  colframe=titlegrammar,
  colback=titlegrammar!03,
  overlay unbroken and first={
    node[
      draw=titlegrammar,
      fill=titlegrammar,
      rotate=270,
      anchor=north west,
      text=white,
      font=bfseries
    ]
    at (frame.north west)
    {LEARN THIS!};
  }
}

definecolor{titlegrammar}{RGB}{255,128,0}

begin{document}

begin{learng}
text goes here
end{learng}

end{document}