About Access SQL

Im Learning SQL Certification training , I would like to ask an Access SQL question.

There is a code like the following, but I would like to add a comparison with a fixed value as an or condition.
I'm new to SQL and it doesn't work.
I would appreciate it if you could teach me.

SELECT A FROM TableA LEFT OUTER JOIN TableB
ON Table A. Column A = Table B. Column B
WHERE Column B IS NULL

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SELECT A FROM TableA LEFT OUTER JOIN TableB
ON Table A. Column A = Table B. Column B
OR Table A. Column A = Fixed value
WHERE Column B IS NULL