You need to use the "Internal Name" of the column. When you create a column in SharePoint, the display name you type may have spaces or special characters, but the Internal Name of the column is what SharePoint actually uses where special characters may be removed or changed with encoding.
Go to your list/library settings and look at the column to edit. If you look in the address bar you can see what the internal name of the column is. Use that internal name within Power Automate.
I made an example below where I made a SharePoint column names "Customer Name"; however, the internal name that was created was "CustomerName" that did not include the space.
If I used "Customer Name" in the filter, it will error since that isn't recognized as a column. When I use the internal name "CustomerName" in the filter, then the flow works correctly.
SharePoint Column Settings
Power Automate Filter Column
(Also in your condition expression the length() looks like it is misspelled as 'lenghth()' so you probably need to correct that as well.)
Let me know if this helps and solved your issue,
