Hi @esther-chan ,
I can see a couple 'gotchas' in your flow which are likely to be causing the error:
1) for the OData filter query, in your first screenshot it looks like your query is supposed to be an expression but the text has been hardcoded - in order for that expression to be valid, you'll need to click on 'Dynamic values' and then the 'Expressions' tab and type your expression there (which will then appear pink as you can see below).
I'm not sure how experienced or technical you are but if you're not familiar with writing expressions, you can use the new preview experience of expressions which is very user friendly. To switch it on, please click on the settings icon to the top right of your screen and choose 'View all Power Automate settings and then switch the 'Experimental features' on.
Depending on your region, your filter query should look like this:
2) Your apply to each action step - please could you show me all of the actions within that part? I can't see the expression you entered in the condition step but this could literally just be the value property in dynamic values (as this will return the list of items) and if that value is greater or equal to 1, you'll provide the user with a table of items, if false, then you'll respond to the user with a message that you don't have that specific CSP in your spreadsheet.
More than happy to help further if needed 😊
Kristine
