The code should be addressed because it needs to be updated. In the meantime to get your site back up you can modify the php error-reporting to ignore "deprecated errors" which means adding this & ~E_DEPRECATED to your error-reporting settings.
In cPanel, you can ignore PHP deprecated errors by modifying the error_reporting setting in your PHP configuration. Using MultiPHP INI Editor (if available):
Log into cPanel: Access your cPanel account.
Navigate to Software: Find the "Software" section.
Click on Select PHP Version: Click on "Select PHP version".
Switch to PHP Options: Click on the "Switch To PHP Options" link, often located in the top-right corner.
Locate error_reporting: Find the error_reporting setting.
Modify the Value: Select the desired option from the drop-down menu next to error_reporting to exclude deprecated errors.
Alternatively, you can manually edit the php.ini file if you have access:
Locate the php.ini file: If you have direct access to your server, you can find the php.ini file.
Find the error_reporting directive: Look for the line that starts with error_reporting.
Change the Value: Modify the value to exclude deprecated errors. For example, if it's set to E_ALL, change it to error_reporting = E_ALL & ~E_DEPRECATED. This setting reports all errors except deprecated ones.
For PHP-FPM:
Navigate to MultiPHP Manager: Go to "WHM / MultiPHP Manager / User Domains".
Find the domain: Search for the domain that needs adjustment.
Go to PHP-FPM Settings: Click on "PHP-FPM Settings".
Edit Error Reporting: Enter E_ALL & ~E_NOTICE & ~E_DEPRECATED in the "Error Reporting" field.
Save changes: Click "Update" to apply the changes.