What you need to ensure is that you have a suitable back-up policy in place.

If the Database is in Full recovery then you need to ensure that you run regular transaction log backups and a daily full backup.

If in simple recovery then you shall need to ensure that you run a full backup at least daily depending on your RPO and RTO.

can you confirm what recovery model is being used by the database?

If it is in full recovery ensure that a full backup has been taken and then run a transaction log backup. After this you may be able to run DBCC Shrinkfile against the

DB Log file