@Sobiepan Unfortunately, No. You cannot check if current list form is new item form or edit item form using JSON formatting.
Check my answer on this thread for detailed information: How to detect Edit vs New when styling custom list forms with JSON?
You have to customize list form using Power Apps to show/hide fields based on form mode (new/edit): Displaying fields when creating new item and them hide them when editing the item, and viceversa. Ho...
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