About "Username already exists in the system users" error message

My YunoHost server

VPS, from OVH

Description of my issue

Username already exists in the system users

I am installing YNH and I wanted to create the first user…
I got this message above!

The username of this YNH user is the same than a sudo username of Debian server.
The issue come from here?

Thank you for your feedback.

JRE

Yes, as the error message suggests …

Thank you Aleks.

Merci cette seconde aides, rapides et précises.

Cordialement, José