How can I define note with stereotype in an activity diagram?

Question

Hello,

using notes with stereotypes seems to work for several diagrams, but I cant get it running on activity diagram.

https://www.plantuml.com/plantuml/uml/RL2zJiGm3Dxz55OdOAbWl2lLIImCiDqBk8tRHfVQLU9ZGRmxlbH236T5-fHyFr_aKp7ATbqJb4kKZJAjA6gCtu0-0usNEUjLmgX9SzVDcLdw7Ylk4is1yrtw1w36ms5IVJx2b9Giohmt99uC_om7F2-ne1-gTFMy706gDiTv-IS6tDMLSrJ1mb-SAJdJjYaAbxP5ae0ZYR-DAaPHi1lwz_FdHzSEjunN7uSdVAFadXbjOLpP5WtODDx_yDWqj_mjwnA7Q1o09Up_AwORmCdllhrV

@startuml
skinparam note {
    backgroundcolor<<green>> green
    bordercolor<<green>> green
}

start
:foo1;
floating note left <<green>>: This is a note
:foo2;

note right <<green>>
  This note is on several
  //lines// and can
  contain <b>HTML</b>
  ====
  * Calling the method ""foo()"" is prohibited
end note
stop
@enduml

I placed the stereotypes at different positions but always get a syntax error. How can I solve this issue?

Thanks,

Robert