To automatically remove formatting from every item you copy, check the “Always paste as Plain Text” option in Preferences.

If you want to paste a particular item as plain text, you can either select it and press ⇧Shift ⏎Return or right-click on it and select “Paste as Plain Text” in the context menu. You can change the “Plain Text” modifier shortcut in Preferences -> Shortcuts.

Please note that Paste does not modify your existing clipboard content automatically — you’ll need to paste items from your current clipboard if you want to remove formatting from them.