Adding custom create button to list-headerpane

Hi all,

I'm working on an instance of SugarServe 10.2.

Following guidance from here and this article (https://support.sugarcrm.com/Documentation/Sugar_Developer/Sugar_Developer_Guide_10.2/Cookbook/Adding_Buttons_to_the_Record_View/#Defining_the_Button_Label) I've been trying to create a custom button on the Accounts module list-headerpane, however after uploading and installing my custom module, and running a Quick Repair and Rebuild, my custom button is still not appearing. Can anyone see what the issue is here?

Here is the manifest file:

<?php

$manifest = array(
'key' => 1,
'name' => 'Accounts Types',
'description' => 'Example Description',
'author' => 'CompanyNet',
'version' => '10.2.0',
'is_uninstallable' => true,
'published_date' => '2020-10-14 15:24:00',
'type' => 'module',
'acceptable_sugar_versions' =>
array(
'exact_matches' => array(
'10.2.0'
),
//or
'regex_matches' => array(
'10.*' //any 10.0 release
),
),
'acceptable_sugar_flavors' =>
array(
'PRO',
'ENT',
'ULT'
),
'readme' => '',
'icon' => '',
'remove_tables' => '',
);

I've added the custom button like so:

custom\modules\Accounts\clients\base\views\list-headerpane\list-headerpane.php

<?php
/*
* Your installation or use of this SugarCRM file is subject to the applicable
* terms available at
* support.sugarcrm.com/.../.
* If you do not agree to all of the applicable terms or do not have the
* authority to bind the entity as an authorized representative, then do not
* install or use this SugarCRM file.
*
* Copyright (C) SugarCRM Inc. All rights reserved.
*/

$viewdefs['base']['view']['list-headerpane'] = array(
'fields' => array(
array(
'name' => 'title',
'type' => 'label',
'default_value' => 'LBL_MODULE_NAME',
),
array(
'name' => 'collection-count',
'type' => 'collection-count',
),
),
'buttons' => array(
array(
'name' => 'create_button',
'type' => 'button',
'label' => 'LBL_CREATE_BUTTON_LABEL',
'css_class' => 'btn-primary',
'acl_action' => 'create',
'route' => array(
'action'=>'create'
)
),
array(
'name' => 'create_SL_button',
'type' => 'button',
'label' => 'LBL_CREATE_SL_BUTTON_LABEL',
'css_class' => 'btn btn-primary',
),
array(
'name' => 'sidebar_toggle',
'type' => 'sidebartoggle',
),
),
);

I've extended the controller as follows:

custom\modules\Accounts\clients\base\views\list-headerpane\list-headerpane.js

/*
* Your installation or use of this SugarCRM file is subject to the applicable
* terms available at
* support.sugarcrm.com/.../.
* If you do not agree to all of the applicable terms or do not have the
* authority to bind the entity as an authorized representative, then do not
* install or use this SugarCRM file.
*
* Copyright (C) SugarCRM Inc. All rights reserved.
*/
/**
* @class View.Views.Base.ListHeaderpaneView
* @alias SUGAR.App.view.views.BaseListHeaderpaneView
* @extends View.Views.Base.HeaderpaneView
*/
({
extendsFrom: 'HeaderpaneView',

/**
* @inheritdoc
*/
initialize: function(options) {
// FIXME: SC-3594 will address having child views extending metadata
// from its parent.
options.meta = _.extend(
{},
app.metadata.getView(null, 'list-headerpane'),
app.metadata.getView(options.module, 'list-headerpane'),
options.meta
);

this._super('initialize', [options]);

//shortcut keys
app.shortcuts.register({
id: 'List:Headerpane:Create',
keys: 'a',
component: this,
description: 'LBL_SHORTCUT_CREATE_RECORD',
handler: function() {
var $createButton = this.$('a[name=create_button]');
if ($createButton.is(':visible') && !$createButton.hasClass('disabled')) {
$createButton.get(0).click();
}
}
});

// Listener for custom button
this.context.on('button:create_SL_button:click', this.create_SL_button, this);
},

create_SL_button: function(evt) {
var accountType = this.model.get(this.def.cn_accounttype_c);

/**
* code goes here
*/

}
})

And I've defined the Button Label as follows:

custom\modules\Accounts\Ext\Language\en_UK.AccountsTypes.php