update app.py

app.py

@@ -99,7 +99,7 @@ if index_choice == 'Custom Formula':
 # Step 6: Calculate and Display Results based on selected index or formula
 if sub_selection and st.button("Calculate Index"):
     # Use the selected dataset from the main and sub-selection as an ImageCollection
-    collection = ee.ImageCollection(sub_selection).filterDate('2020-01-01', '2020-1-31')
+    collection = ee.ImageCollection(data[main_selection]["sub_options"][sub_selection]).filterDate('2020-01-01', '2020-1-31')
     image = collection.first()  # Using the first image in the collection as an example
 
     result_image = None