E: Unable to locate package issue

I’m trying to install the ‘stressapptest’ pkg.
but the error occurred like as below.

firefly@firefly:~$ sudo apt-get install stressapptest
Reading package lists… Done
Building dependency tree
Reading state information… Done
E: Unable to locate package stressapptest

So, I tried something as below cmd but the result was same.

firefly@firefly:~/proj$ sudo apt update
firefly@firefly:~/proj$ sudo add-apt-repository universe
firefly@firefly:~/proj$ sudo add-apt-repository multiverse

How can I solve this problem ?

It is not a problem. Just because Ubuntu have no stressapptest for arm64, so you can’t find it
check the link:
https://packages.ubuntu.com/search?suite=default&section=all&arch=any&lang=en&keywords=stressapptest&searchon=names
Ubuntu only provides amd64 version
So you have to build stressapptest from source, but i seem to remember firefly firmware already come with the stressapptest

You mean that ‘stressapptest’ is already installed on the firefly Ubuntu ?

OK Thanks a lot.
I have checked it works well.