Yes. Whenever you like. Under “Projection” go into the detail and edit the key parameters of your investment objective, such as your current investment, desired amount, time horizon, etc.
Select the portfolio with the desired objective in the bar below the overall
performance of your account
Click on "Make a projection" in the white frame "Objective"
Modify the fields you want and click "Apply"
Validate the different fields
Done. Your changes are taken into account immediately.