Kdjykuj

How do I show the content of other sites in my system configuration, Please provide me a solution

 <group id="general" translate="label" type="text" sortOrder="10" showInDefault="1" showInWebsite="0"

                   showInStore="0">

                <label>abcd</label>

                <frontend_model>xxyyBlockAdminhtmlSystemConfigExtensions</frontend_model>

                <comment>  

                <![CDATA[

                <iframe id="mp-core-partners" src="https://www.123.com/core/sbc.html" frameborder="0" scrolling="no" width="100%" height="1700px" style="min-height: 800px;"></iframe>

                ]]>

                </comment>

</group>

Remove comment tag if you want to add the same in system config.
You have already defined frontend_model so create a block file with specified value in it with following code.

<?php



namespace [Vendor][Module]BlockAdminhtmlFormField;



class Customfield extends MagentoConfigBlockSystemConfigFormField

{

    /**

     * @param MagentoBackendBlockTemplateContext $context

     * @param array $data

     */

    public function __construct(

        MagentoBackendBlockTemplateContext $context,

        array $data = 

        )

    {

        parent::__construct($context, $data);

    }



    /**

     * Set template.

     */

    protected function _construct()

    {

        parent::_construct();

        $this->setTemplate('[Vendor]_[Module]::system/form/field/custom.phtml');

    }



    public function render(MagentoFrameworkDataFormElementAbstractElement $element)

    {

        // Remove scope label

        $element->unsScope()->unsCanUseWebsiteValue()->unsCanUseDefaultValue();

        $configValue = (string) $element->getValue();

        $values = ;

        if (strlen($configValue) > 0) {

            $values = explode(',', $configValue);

        }

        $this->setConfigValue($values);



        return parent::render($element);

    }



    public function getSelectedAttributes()

    {

        $options = ;



        return $options;

    }



    /**

     * Return element html.

     *

     * @param MagentoFrameworkDataFormElementAbstractElement $element

     *

     * @return string

     * @SuppressWarnings(PHPMD.UnusedFormalParameter)

     */

    protected function _getElementHtml(MagentoFrameworkDataFormElementAbstractElement $element)

    {

        return $this->_toHtml();

    }

}

The create a phtml file

[Vendor]/[Module]/view/adminhtml/templates/system/form/field/custom.phtml

With whatever you want to add like

<iframe id="mp-core-partners" src="https://www.123.com/core/sbc.html" frameborder="0" scrolling="no" width="100%" height="1700px" style="min-height: 800px;"></iframe>