Step 1: Create di.xml file in etc/frontend. Put below content in it.

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="MagentoCatalogModelProduct">
		<plugin name="change_product" type="MagemonkeysChangepricePluginChangeProductPrice" sortOrder="1" disabled="false" />
  	</type>
</config>

Step 2: Create di.xml file in etc/webapi_rest. Put below content in it.

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="MagentoCatalogModelProduct">
		<plugin name="change_product" type="MagemonkeysChangepricePluginChangeProductPrice" sortOrder="1" disabled="false" />
  	</type>
</config>

If you add this plugin only in front-end area then the change price functionality will not work on checkout and cart page. So you have to create another di.xml file in etc/webapi_rest folder.

Step 3: Create Plugin Folder and Create ChangeProductPrice.php in it. Put Below content in it.

<?php
namespace MagemonkeysChangepricePlugin;
 
class ChangeProductPrice
{
    public function afterGetPrice(MagentoCatalogModelProduct $subject, $result)
    {
        /* Put your logic here and return the $result */
        return $result+10;
    }
}

Step 4: After that run the upgrade, compile, static-content deploy and flush cache command through the terminal as below. And you can check now.

php -dmemory_limit=6G bin/magento setup:upgrade
php -dmemory_limit=6G bin/magento setup:di:compile
php -dmemory_limit=6G bin/magento setup:static-content:deploy -f
php -dmemory_limit=6G bin/magento cache:flush