How to update Sketchup 2019.1. to 2019.3:

Hi, I have a problem with my Sketchup. I downloaded a Thea render, but my Sketchup 2019.1. doesnt support Thea render. I need a Sketchup 2019.3. How to do that? Thank you

You can download the installer of 2019.3 from here: SketchUp Pro 2019-EN x64 f. Windows

Right click on downloaded file and chose Run as administrator to install this update.

I installed it, but it wants from me to buy a license, it doesnt update the older version.

Have you tried restarting your computer after the update?
And please update your forum profile… That information helps us to help you.

2019.3 is a Maintenance Release. If you had 2019.1 version already on your computer Installing the Maintenance Release over an existing version should have keep your licence intact if you chose the same location for installation.
Are you really sure you have 2 instances of Sketchup 2019 in your computer?
Anyway you should be able to enter your existing licence data’s after reinstalling.