I trust you are well,
It is not possible to change your domain unless you cancel or signup a new one.
You may have signed up a subdomain, pls recheck, alternatively, you can email firstname.lastname@example.org to restore your settings.
If you require further assistance,
please send a message to our WhatsApp helpline: https://whatsapp.afrihost.com
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or see our FAQ page: http://faq.afrihost.com