Add a button to Command Bar of a SharePoint online Library All Item view

[Supun Bulathsinghala]

I have a requirement to add a new button to the Command Bar (Just above the Lst View with New, Upload, Sync, Share,... buttons). using Custom Actions. 

I couldn't find a way to add a custom action to the Command Bar / Hero bar. 

Appreciate your support on this

[#2]

AFAIK, this is currently not possible.

[#3]

Agree, I'm not aware of way of extending that bar...you can extend the ribbon, the ECB...but not sure about that bar...maybe by injecting some JS?

[#4]

Yep I can inject some JS, but thought of checking first if there's a way to add a button to the command bar similar to Ribbon and ECB. 

Thanks guys for the responses. 

[#5]

I've done this before, like Juan mentioned, just by injecting JS, its the only way.

[#6]

Can you please give me a example for injecting JavaScript to add CommandBar button?