I found the documentation, it is in iNotes administration although I think it is generic Notes functionality since you can use OpenSocial gadgets also in Notes client.

So it stills says I can use Edit OAuth data button and it is only available when OAuth data is available in widget.

OK, I might be blind but I am looking at this and do not see any button

same here!  edit oauth button disappeared (i've all role in db)

Do you set $enable_ee and enable_ee in your notes.ini?

Yes, it is there, I mean these settings

also for me, i've both sets on my notes.ii (i've insert in policy setting in public beta)

I see it now, it is grey so not very visible. Also the documentation says "Edit OAuth Data button on top of the form" whic is not correct.

Another thing is that I have JIRA widget that has OAuth, I configured it as OpenSocial gadget. It has OAuth section in the extension.xml

-<OAuth>-<Service name=""><Access url="http://jira.interconnect.gr/plugins/servlet/oauth/access-token" param_location="HEADER" method="POST"/><Authorization url="http://jira.interconnect.gr/plugins/servlet/oauth/authorize?oauth_callback=http%3A%2F%2Foauth.gmodules.com%2Fgadgets%2Foauthcallback"/><Request url="http://jira.interconnect.gr/plugins/servlet/oauth/request-token" param_location="HEADER" method="POST"/></Service></OAuth>

However the widget document does not show OAuth data section. Why is that?

Alex, was this a Widget document that you had in your Widget catalog with your public beta installation?  Or did you create this Widget after installing 9.0 and replacing your Widget catalog template design?