Please note: Only own recipes can be edited. It is not possible to edit Lifesum recipes.
Please go to the Progress tab and then click on Favorites and then go to Recipes.

Then click on the recipe in question. Top right hand you see an icon showing a pen. Click on it and you will get to the edit mode. You will then be able to change the recipe by going through the recipe clicking on "Next" top right hand and then save the changes by clicking on Save top right at the end of the recipe flow.
Make sure that you are in Favorites when doing that - editing is not possible in tracked recipes.