Where can I find an apk to be able to do introductory tests using Katalon studio?
You can go to this repository find what you are looking for.
You should find a section for Application Under Test (AUT) under which there will be a file named APIDemos.apk.
Alternatively, this is also possible within Katalon Studio if you go to File > New Sample Project > Sample Android Mobile Tests.
the repository is a test project, only I only open it from katalon?
Yes, it a sample project that you can run on Katalon to learn basics or to check a feature. You can open it on Katalon as shown above or you can also go directly to the repository on Github and download all the files from there as well. Cheers.
Apk demo, is no longer in repository
What do you mean? You need to click on ‘Download’ button next to the ‘History’ button. I just tried and was able to download it.
if you are right the project repository if it works, what I mean is that, in the requisisto to execute the project asks to install an APIDemos.apk, the APIDemos.apk no longer exists in the repository. you can see it, it is in the description in the lower part of the project