Need help error installing the ARC APEX

[Shakshyam Kafle]

Hi everyone,
I am new to APEX software and I am trying to install ARC APEX on my computer but the following error occurs. I have added a screenshot of the problem. 
I am seeking for help here. 
Thank you in advanced.

[Luca Doro]

Hi,

Let's begin with the basics. Which version of ArcGIS do you have installed on your computer? 

Depending on the version you have downloaded from the Blackland Research Center website, version 10.7.1 or version 10.8.2 is required.

Luca