Isolation forest

Hello,
I have a data set with retrieval times, i.e. just a column with a number representing seconds. I want to filter out outliers from this data set using the IsolationForest Node.
Now my question:
Is this possible in my case with only one column ?
What do I have to consider, since my workflow does not deliver any results?

Try to add row number as a first column. Also, if possible, please place you workflow