Send Mail | Insert Code | How to use it? What's it for?

Send Mail | Insert Code | How to use it? What's it for?

Hi All,

After a few hours of web searching, I'm struggling to figure out how to use the insert code feature in send mail.

I'm trying to create a dynamic reference code based on the current year.

If the year is 2023 then the code would be DEPOSIT23. Next year it would be DEPOSIT24.

I'm able to accomplish this in Deluge using the sendmail function but I saw the insert code option in Send Mail Messages and thought that might be a simpler solution.

So now I'm on a mission to figure out what insert code does.

Thanks in advance for your help!