Hi @Skybluekid ,
You are entering the 'properties' incorrectly. Let's take this range as example:

In our flow, we will first convert this range to a table, which will contains a header (col1, col2, col3 and col4) and a single record (entry1, entry2, null, entry4):

Now let's update this record, to change it's value from col2. To achieve it, we need to pass an object as 'properties' input, where the key will be the name of the column that we want to update (col2, in our case) and the value will be the new data to be assigned (entry456789, in our case), as highlighted below:

The flow runs successfully:

And this is the output:

Now let's do the same thing, but with changes for both col2 and col3. I've removed the table format from the range (as the table will be created dynamically) and set 'col2' to 'entry2' again:

Output:

Also, I'm sharing here some articles about some strategies to work with Power Automate and Excel (they must be basic for you, but it can help any other starter user that reads this post):
- Integrating Excel Tables and Power Automate: http://digitalmill.net/2023/07/17/integrating-power-automate-and-excel-tables/
- Reading data from Excel tables: http://digitalmill.net/2023/07/19/reading-data-from-excel-tables-in-power-automate/
- Inserting/updating data in Excel tables: http://digitalmill.net/2023/07/24/inserting-and-updating-data-into-excel-tables-with-power-automate/
- Working with Excel ranges: http://digitalmill.net/2023/09/01/accessing-excel-ranges-with-power-automate/
Let me know if it works for you or if you need any additional help!
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