Hi @AshishJaiswal
You will have to think about how you are going to identify them? Is it by email? Will you store the responders email in the list?
If so, after your flow triggers with get response and you get the response details, you could run the get items action with a filter on the column containing the email of the user i.e.
emailcolumn eq 'responders email'
then with a condition you can check the length of the response with the expression length(value from get items) and if the length is greater than 0, they exist and you need to run an Update Item using the ID from the Get Items, if it is less than 0, you can run the create item.
Hope that makes sense.
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
Cheers,
Damien
P.S. take a look at my new blog here
