I would recommend in the installation instructions under 1. to directly save the .ppam add-in into the folder C:\Users\user_name\Appdata\Roaming\Microsoft\Addins as mentioned in https://bytemeta.vip/index.php/repo/Jonathan-LeRoux/IguanaTex/issues/28, since Microsoft blocked IguaneTax when I saved it into the default Download-folder under Windows 11.
I would recommend in the installation instructions under 1. to directly save the .ppam add-in into the folder
C:\Users\user_name\Appdata\Roaming\Microsoft\Addins
as mentioned in https://bytemeta.vip/index.php/repo/Jonathan-LeRoux/IguanaTex/issues/28, since Microsoft blocked IguaneTax when I saved it into the default Download-folder under Windows 11.