i think its a QWeb Template which is different from .xml files

see this file:

addons/mail/static/src/components/chatter_topbar/chatter_topbar.xml

check the path, it resides in static folder.

note: 3 more are there in addons path, don't know which one and how to inherit and modify.

Hi,

Inherit 'ChatterTopbar' templates and add a label for the button send message  with the desired one

<?xml version="1.0" encoding="UTF-8"?>
<templates xml:space="preserve">
        <t t-inherit="mail.ChatterTopbar" t-inherit-mode="extension">
<xpath expr="//button[hasclass('o_ChatterTopbar_buttonSendMessage')]" position="attributes">
         <attribute name="labelaria-label" >custom name</attribute>
          </xpath>
          </t>
</templates>

Also, Add your xml file in manifest as below,

'assets': {
'web.assets_qweb': [
'your_custom_module/static/src/chatter_topbar.xml',
],
},

Replace custom name with the desired name.

Hope it helps,

This is a work-around. Try inherit the view, replace the button with your new button using all the same attribute except the label 

Any luck anyone?

Hello SmithJohn45

Thank you for your answer

I already found those static files but don't talk about them to have more ideas

And like you i don't know how to override those files. I tried with t-extend and other but nothing works for now