You are using an old version of WordPress. Because you do not have proper access to the panel, you need to update as follows:
- Access your FTP and copy the files that are there to your computer as a backup.
- Download the latest version of WordPress here: https://wordpress.org/
- If they are zipped, extract the downloaded file.
- Upload and replace
IMPORTANT:
Do not replace the following folder:
public_html / wp-content /
Do not replace the following file:
public_html / wp-config.php /
Ps: Sorry for my bad English.