SQL Server Agent Job failure
You included the following in your question:

Executed as user: ...tabase backup. [SQLSTATE 42000] (Error 4214) BACKUP LOG is terminating abnormally. [SQLSTATE 42000] (Error 3013).

The error you're seeing (error 4214) indicates that there has been no current database backup performed.
This is the actual text of that error message:

BACKUP LOG cannot be performed because there is no current database backup.

I was able to look that up using this query:
SELECT m.message_id
    , m.severity
    , m.text
FROM sys.messages m
WHERE m.message_id = 4214
    AND m.language_id = 1033; --Show the English version of the message

This means you need to ensure you take a full database backup in order for the BACKUP LOG to complete without error.
If, by chance, you changed the recovery model of the database from simple recovery to full recovery since the last full backup occurred, you won't be able to do a BACKUP LOG until you take another full database backup.  Changing the recovery model doesn't actually take effect until a full database backup completes.  The following excerpt was taken from the Microsoft Docs:


Immediately after switching to the full recovery model or bulk-logged recovery model, take a full or differential database backup to start the log chain.
NOTE: The switch to the full or bulk-logged recovery model takes effect only after the first data backup.