When the users come back from their temporary leave or temporary assignment, revert their status to Active.​​
They can access Kintone once their status is changed. ​​

1. Access Kintone users & system administration.
   Accessing Kintone users & system administration

2. Click Departments & users.
   

3. In the search box, enter the display name or login name of the user to find the target user.
   You can also expand the department tree and select the target user.

4. Click the Change icon.
   

5. In the Account status section, set Status to Active.
   

6. Click Change user information.