How can I upload or edit in Bulk my employees' identification numbers?

Do you have a higher role? Then make identification number a mandatory field in all employees profile. 

How? Go to Configutation >> Automations >> User accesses 

There find and activate the following switch Establish mandatory identification number when creating employees.

The system will want you if there are employees without identification number within your database and you will have the option to download a template to fill out this information. Keep in mind that the switch will be activated once the identification number has been added to all employees' profiles. 

If all employees have this information in their profiles, the switch will be activated and in the following bulk upload, this field will be mandatory.