Unzip the downloaded prologinexcel_setup.zip folder.

Run the setup.exe file.

You probably get some security warning such as this one (According to Windows and Excel versions, security warning may have different aspect):

Click on Install.

You may have others security warning coming from anti-virus. Accept the installation.

When installation is finished, you probably get a message such as:

Click on Close.

Open a new Excel workbook.
In the left of the top menu, go to File:

On the left, click on Options.

You get this new window:

On the left, select Add-ins.
Then at the back select COM add-ins.
Then click on the Go... button.

You get this new window:

Thick the prologinexcel check-box.
Click the OK button.

On the left, select Customize Ribbon:

On the right, thick the PliX box.

Your Excel workbook has now an additional menu item Plix.

In a cell, type exactly (or copy/paste):
?-  true.

Double click on this cell:

You get a message box with “yes“.

It works!