Re: Flow that Creates and Updates from Two SharePoint Lists
ou can use the trigger 'When an item is created or modified' instead, but then we need a value in List B that links it to List A. I suggest you add a column in List B called something like ListA_ID. So in addition to adding Task name and Status Value, you also add the ID. Then we can check when a new item is added if it already exists, then we should update, if it doesn't exist, we create a new one.
So when a new item is created in List A, retrieve items in List B but filter by ID by adding this to the Filter Query
ListA_ID eq 'INSERT dynamic value ID'

Then check if the output is empty, if so create a new item, otherwise update an existing one.
The expression is just empty() and then y add the dynamic content of the body inside the ()
and just write true in is equal to-field


Hope it helps!