(using the plantUML render plugin

some examples from https://real-world-plantuml.com/umls/4561383312064512

<uml>

skinparam activity {

  FontColor          white
  AttributeFontColor white
  FontSize           17
  AttributeFontSize  15
  AttributeFontname  Droid Sans Mono
  BackgroundColor    #527BC6
  BorderColor        black
  ArrowColor         #222266

}

partition start { (*) –> if “steam pump\nmounted ?” then

1. right→ [No] “echo a warning”
2. → (*)

else

  if "linked to\norchestra ?" then
      -right-> [No] "echo location "
      --> (*)
  else
      if "flying ?" then
          -right-> [No] "start flying"
          if "started" then
              --> [No] "exit stage left"
              --> (*)
          else
              --> [Yes] ===A===
          endif
      else
          --> [Yes] ===A===
      endif
      --> "start chasing elephants"
      if "started" then
          --> [No] "exit 2"
          --> (*)
      else
          --> [Yes] (*)
      endif
  endif

endif } <uml>