Root partition is filling up - UTM 9.7


our SG 125 rev.1 is still sending email:

Root partition is filling up - please check. Current usage: 93%


HA Status          : HA SLAVE (node id: 1)

System Uptime      : 0 days 1 hour 6 minutes

System Load        : 0.10

System Version     : Sophos UTM 9.705-3


Please refer to the manual for detailed instructions.

I tried to use this tutorial but in thsi folder are not big files. Can you help me what I should do please? I am not so experienced with linux.