Change the value in a column based on a value in another column

Hello,

in one community I found a command to change the value in one column based on another column, but it doesn't work properly. Could you advise me?

The problem is as follows:
I have an ORDER_STATUS column and a load_date column. I want to change the value in the load_date column based on the value in the ORDER_STATUS column. If the ORDER_STATUS column has the value "CLAW", I want the value "NA: CLAW" to be added to the load_date column.
The function should be correct (I indicated it in the picture), but it does not do what it should.

Can you advise please? Thank you very much.