To adjust your macro targets at anytime, go to the Track page and click 'View trends' underneath the Macro tracker.
Then, once you're on the Macro trends page, click the settings option in the top right hand corner.
Once you are in the settings, you will be able to adjust your calories and macro targets. Make sure that you have the 'Custom' option switched on.
Once you have edited the calorie and macro targets, make sure to click 'Save changes'. Your targets will now be updated in the app.
Watch this video to learn how the Macro and Calorie tracking feature works: