Thank You @devansh-webkul, Again I tries and found that I haven't created Class File so that was not working but for now in admin panel in place of label admin::app.admin.system.paypal-smart-button is showing.
Below are the code:
packages\Webkul\Ccavenue\src\Confif\Syatem.php
<?php
return [
[
'key' => 'sales.paymentmethods.ccavenue',
'name' => 'admin::app.admin.system.ccavenue',
'sort' => 3,
'fields' => [
[
'name' => 'title',
'title' => 'admin::app.admin.system.title',
'type' => 'text',
'validation' => 'required',
'channel_based' => false,
'locale_based' => true,
], [
'name' => 'description',
'title' => 'admin::app.admin.system.description',
'type' => 'textarea',
'channel_based' => false,
'locale_based' => true,
], [
'name' => 'business_account',
'title' => 'admin::app.admin.system.business-account',
'type' => 'select',
'type' => 'text',
'validation' => 'required',
], [
'name' => 'active',
'title' => 'admin::app.admin.system.status',
'type' => 'boolean',
'validation' => 'required',
'channel_based' => false,
'locale_based' => true
], [
'name' => 'sandbox',
'title' => 'admin::app.admin.system.sandbox',
'type' => 'boolean',
'validation' => 'required',
'channel_based' => false,
'locale_based' => true,
], [
'name' => 'sort',
'title' => 'admin::app.admin.system.sort_order',
'type' => 'select',
'options' => [
[
'title' => '1',
'value' => 1,
], [
'title' => '2',
'value' => 2,
], [
'title' => '3',
'value' => 3,
], [
'title' => '4',
'value' => 4,
],
],
]
]
]
];
packages\Webkul\Ccavenue\src\Config\paymentmethods.php
<?php
return [
'ccavenue' => [
'code' => 'ccavenue',
'title' => 'Ccavenue',
'description' => 'Ccavenue',
'class' => 'Webkul\Ccavenue\Payment\Ccavenue',
'sandbox' => true,
'active' => true,
'sort' => 4,
]
];
Output is:-

Please Help me..
Thank You in advance.