I have built a flow that reads the rows of an Excel document to populate items in Planner. One of the steps is to check and see if a Planner Bucket exists based on one of the Columns, and if it doesn't exist, create the Bucket in Planner. If I run the flow one row at a time, it works. If the Bucket already exists, it works. The challenge is that with the setting "Split On", the flow starts processing multiple rows concurrently and each Flow creates a new Bucket. I want the Flow to loop through the selected rows consecutively so it doesn't create multiple Buckets. When I click the "Split On" to the off position, I can't save the settings. I'm assuming it needs a new trigger, but I don't know what is the new trigger. (Note: I'm very new to Power Automate.)

All feedback is welcomed. Thank you.
FYI: Here's the entire flow:
