In kintone, a school-cap icon appears at the top of the screen during the 30-day free trial period.

When the free trial period is over, the school-cap icon will automatically disappear from all users' screens.

If you want to hide the school-cap icon during the free trial period, configure the permission settings so that users do not have permission to create apps. The school-cap icon is not displayed for users who do not have permission to create apps.
For details on how to configure the permission to create apps, refer to the following page.
Permission to create apps

Note that cybozu.com administrators have all permissions for kintone.
For this reason, the school-cap icon will be visible to cybozu.com administrators even if the permission to create apps is not explicitly granted to them.