The trigger "When an item is modified" is not supported in sharepoint connector in microsoft flow currently.
If you want to trigger an flow when an item is modifed, you could only use the trigger "When an item is created or modified".
As an alternative way, you could:
1. Add a Yes/No type column "DateIsChanged" in the list, the default value of column "DateIsChanged" is false.
2. Everytime when create an item in the list, keep the column "DateIsChanged" be false.
3. Everytime when change the date in the list, keep the column "DateIsChanged" be true.
4. Create a flow with trigger "When an item is created or modified", add a Condition to check if the "DateIsChanged" column value is equal to true, in the If yes branch of the Condition, add the approval action for date changed, In the If no branch of the Condition, add the approval action for new item created.
Explore the latest innovations, learn from product experts and partners, level up your skillset, and create connections from around the world.
Learn to digitize and optimize business processes and connect all your applications to share data in real time.
Attend in person or online, there are incredible conferences and events happening all throughout the month of September.