The phrase could refer to a few different things depending on what you're trying to do. The two most likely interpretations are:
Click . This will highlight all text objects in your drawing while ignoring everything else. If you are having trouble editing text after the update Autodesk AutoCAD LT 2019.1 Update Only
You are looking for the specific 2019.1 update file (a "patch") to fix bugs or performance issues in an existing installation of AutoCAD LT 2019. The phrase could refer to a few different