https://git.libreoffice.org/core/+blame/master/sc/uiconfig/scalc/ui/dataproviderdlg.ui#25 Action button with no mnemonic and the wrong (as in locally unconventional) spelling. https://translations.documentfoundation.org/translate/libo_ui-master/scmessages/en/?checksum=5ac24d79c04c84a3#comments
It seems the issue has been fixed in the meantime.
Yep, Caolán fixed it in a7e883f6fc8665f9d0fb522e1c2be41734ff8542