This is the flow steps used to create and update items in SharePoint list based on Excel values.

The condition verifies whether the length of the retrieved items from SharePoint is greater than zero. If it is, it updates the existing data in the SharePoint list; otherwise, it creates a new item.
length(outputs('Get_items')?['body/value'])

In this case, retrieve the item from SharePoint that requires updating, and proceed with the necessary updates.
outputs('List_rows_present_in_a_table')?['body/value']
items('Apply_to_each')?['WTRF']
first(outputs('Get_items')?['body/value'])?['id']
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Regards,
Santhosh Balakrishnan
Apps4.Pro - Trusted Office365 T2T Migration partner. Migrate Exchange, SharePoint, Microsoft Teams, Stream, Yammer, Power Platform between tenants.
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