Help new install Mathematica on Raspberry Pi 5

Team, I am very rusty on this one. I have been about 4 years away and returning to a new RB Pi 5.o.
The problem is that I do not know how to get started with installation of Mathematica.

I downloaded an Installation script. But from here I am lost. I click the file, but only opens a text file with a code. Can not get to go any further.

Ok./. was able to install from the Root .
But the WritePin 4 does not bring the led to high . Anyone has this issue?

If tour operating system is the native RaspbianOS It should be available through APT package manager system just likes any Debian based system. Just sudo apt-get install wolfram-*

Thank you. This works and is running. But seen there is nothing new here posted several years now.
Not able to read the GPIO.

Mathematica can be very easily installed on the Raspberry Pi 5 in just a few clicks, see the instructions here:
https://www.21stcenturycoding.net,
specifically at
Prepare.
Then select Mathematica under ‘Programming’, and it runs notebooks as on your desktop or laptop.