Using "apologize" without "for"

Solution 1:

The OED has only one citation, from Swift, showing the transitive use of apologize, which it describes as ‘obsolete’. That suggests that in modern English it is ungrammatical.

Solution 2:

Apologize is almost always (excluding some rare uses) an intransitive verb; however, with that said, you will often hear people (in the US) say things like, "I apologize [that] the event didn't go as planned." Technically it needs that as a conjunction, but there's a strong trend in the US toward omitting that when it's used conjunctively. Personally, I don't care for it, but you will hear (and read) that sometimes.

You cannot use that sentence as a complete sentence as is though. It needs a preposition (for/about/to)

Solution 3:

It shows up in modern Non-apology apologies:

Attorney and business ethics expert Lauren Bloom, author of The Art of the Apology, mentions the "if apology" as a favorite of politicians, with lines such as "I apologize if I offended anyone".