Join 2 tables without create table

Have a basic query that I need help with.

I have 2 tables, Table A and Table B which I want to join.

I want to put a column from Table B onto Table A using common Key.

The catch is that instead of using CREATE TABLE Table C, I want to modify Table A directly with my new column.

What do I add to my existing code?

SELECT *, Table A.Column as NewColumn from Table A
LEFT JOIN Table B
ON Table A.Key = Table B.key;