Back up transaction logs on a daily or weekly basis to keep them small.
Truncating the Transaction Log
When MS SQL Server finishes backing up the transaction log, it automatically truncates the inactive portion of the transaction log. This inactive portion contains completed transactions and is no longer used during the recovery process. Conversely, the active portion of the transaction log contains transactions that are still running and have not yet completed. MS SQL Server reuses this truncated, inactive space in the transaction log instead of allowing the transaction log to continue to grow and use more space.
Although the transaction log may be truncated manually, Henry Schein One strongly recommends that you do not do this, as it breaks the log backup chain. Until a full database backup is created, the database is not protected from media failure. Use manual log truncation only in very special circumstances, and create a full database backup as soon as it is practical.
Refer to the following:
MS SQL Server 2019