1. To upload a certificate for your vacations, just type 'upload' command into the AttendanceBot. 

2. You'll be presented with a list of your recent vacations and you can tap on the Upload button against the vacation for which you want to upload a certificate. 

3. After you select upload for the required leave, you will receive a prompt from AttendanceBot which looks something like this 

4. Upload the file into the Atten