php bin/magento admin:user:create –admin-user selman
Create or edit an administrator
Use this command to create a new administrator or to edit an existing administrator. If you’re editing an administrator, only the first name, last name, and password can be edited.
Command usage:
php bin/magento admin:user:create [--<parameter_name>=<value>, ...]
The password must be at least 7 characters in length and must include at least one alphabetic and at least one numeric character.
We recommend a longer, more complex password. Enclose the entire password string in single quotes. For example, --admin-password=''A0b9%t_3g'.