Hi, i'm trying to extend composer to change the 'send' button removing the text and placing an icon, from mail module

<templates xml:space="preserve">
     <div t-name="mail.ChatComposer" class="o_chat_composer">
         <div class="o_composer_attachments_list"/>
         <t t-if="widget.extended">
             <div class="o_composer_subject">
                 <input tabindex="1" type="text" placeholder="Subject"></input>
                 <div class="btn-group o_composer_buttons">
                    <button tabindex="3" class="btn btn-sm btn-primary o_composer_button_send" type="button"><t t-esc="widget.options.send_text"/></button>
                    <button tabindex="4" class="btn btn-sm btn-icon fa fa-smile-o o_composer_button_emoji" type="button" data-toggle="popover"/>
                    <button tabindex="5" class="btn btn-sm btn-icon fa fa-paperclip o_composer_button_add_attachment" type="button"/>
                 </div>
             </div>
         </t>
         <div t-attf-class="o_composer #{widget.extended ? 'o_extended_composer' : ''}">
             <div class="o_composer_input">
                 <textarea class="o_composer_text_field" tabindex="2" placeholder="Write something..."/>
             </div>
             <t t-if="!widget.extended">
                 <div class="btn-group o_composer_buttons">
                    <button tabindex="3" class="btn btn-sm btn-primary o_composer_button_send" type="button"><t t-esc="widget.options.send_text"/></button>
                    <button tabindex="4" class="btn btn-sm btn-icon fa fa-smile-o o_composer_button_emoji" type="button" data-toggle="popover"/>
                    <button tabindex="5" class="btn btn-sm btn-icon fa fa-paperclip o_composer_button_add_attachment" type="button"/>
                 </div>
             </t>
         </div>
         <span class="hide">
            <t t-call="HiddenInputFile">
                <t t-set="fileupload_id" t-value="widget.fileupload_id"/>
                <t t-set="fileupload_action" t-translation="off">/web/binary/upload_attachment</t>
                <input type="hidden" name="model" value="mail.compose.message"/>
                <input type="hidden" name="id" value="0"/>
                <input type="hidden" name="session_id" t-att-value="widget.session.session_id"/>
            </t>
         </span>
         <span t-att-class="widget.emoji_container_classname"></span>
    </div>

My current approach:

<t t-extend="mail.ChatComposer">
    <t t-jquery=".o_chat_composer" t-operation="replace">
        <t t-if="widget.extended">
            <div class="o_composer_subject">
                <input tabindex="1" type="text" placeholder="Subject"></input>
                <div class="btn-group o_composer_buttons">
                    <button tabindex="4" class="btn btn-sm btn-icon fa fa-smile-o o_composer_button_emoji" type="button" data-toggle="popover"/>
                    <button tabindex="5" class="btn btn-sm btn-icon fa fa-paperclip o_composer_button_add_attachment" type="button"/>
                    <button tabindex="3" class="btn btn-sm btn-primary o_composer_button_send" type="button"><t t-esc="widget.options.send_text"/></button>
                </div>
            </div>
        </t>
        <div t-attf-class="o_composer #{widget.extended ? 'o_extended_composer' : ''}">
            <div class="o_composer_input">
                <textarea class="o_composer_text_field" tabindex="2" placeholder="Write something..."/>
            </div>
            <t t-if="!widget.extended">
                <div class="btn-group o_composer_buttons">
                    <button tabindex="4" class="btn btn-sm btn-icon fa fa-smile-o o_composer_button_emoji" type="button" data-toggle="popover"/>
                    <button tabindex="5" class="btn btn-sm btn-icon fa fa-paperclip o_composer_button_add_attachment" type="button"/>
                    <button tabindex="3" class="btn btn-sm btn-icon fa fa-send o_composer_button_send" type="button"/><!--<t t-esc="widget.options.send_text"/></button>-->
                </div>
            </t>
        </div>
    </t>
</t>

But is not working at all, of course i have the file referenced in qweb part of manifest file.

Any idea of what i'm doing wrong?