How to use email address as user instead of a word

My Cloud OS 5 Personal & Network Attached Storage My Cloud EX Series
1

When I set upWDEX4100 I put a word as username and password How do I change it so I would use an email address instead of that word

2

Hi @allWD,

Please contact the WD Technical Support team for best assistance and troubleshooting:
https://support-en.wd.com/app/ask