To setup Inventory Adjustment Reasons, go to Setup> System Settings > Products/Inventory >> Inventory Adjustment Reason Codes
After following the above steps, when you click on "+" icon, to add a new reason code, the following options will show-up.
Add in the Reason for which type of adjustment you want to add a new reason codes to.
Enter the Reason Code, select the Adjustment Type from the dropdown and select the Income Expense Account to hit when selected this reason code while Adjusting the Inventory. And after entering the Code click on "Save" to add the reason code.
Enter the Reason Code, select the Adjustment Type from the dropdown and select the Income Expense Account to hit when selected this reason code while Adjusting the Inventory. And after entering the Code click on "Save" to add the reason code.
To Update the existing Reason code, click on the reason code and select "Update" option as show below
After clicking on "Update" option, you can update the reason code and click on "Save" to update the existing Reason Code.