How to add a customized ToolButton to the floating Quick Action Toolbar? [Acrobat Pro DC]

Hi experts,

I'm scripting a plug-in which is basically a SelectionServer tool called by "My ToolButton". However, it would help me enormously if I can add "My ToolButton" to the floating quick action toolbar that appears when a text is selected. I have read the documentation but I did not find anything related or maybe I'm not looking in the right direction. Any help would be greatly appreciated.

Regards,

Febo.