Hi @elenimou,
Welcome to the Speciforum! 
There are five permission levels in Specify 6, each with various levels of permissions. These are configurable by Administrator users, or those who have permission to perform all actions in Specify 6.
- Guest
- Limited Access
- Full Access
- Manager
- Administrator (has all permissions)
It is possible your user is under the “Managers” list of users, but not part of the “Administrator” list. To make a change like this, you will need to use a “Administrator” user. If you need help or would like us to perform this for you, you can send a backup of the database to us to take a look at!
For reference, see Adding Users and Setting Permissions