Thank you, I got it! So, I must enter my project folder, and then call adt by its full path.
So, some more guidance needed, if you please
Here is how my folder looks like now:
folder ~/Projects/Air_FarmAndMine/Project-LInux now contains subfolders:
bin - with .swf file and assets
cert - with certificate
dist - empty, has empty subfolder FM
Also a file application.xml is inside, too
Now I call cd ~/Projects/Air_FarmAndMine/Project-LInux
and I get inside the folder. And now I call:
bash ~/Tools/Air/331/bin/adt -package -storetype pkcs12 -keystore cert/GPCAir.p12 -storepass fd -target bundle dist/FM application.xml -C bin
When I call this, I receive "output file is not writeable" error. So, instead, I call
sudo bash ~/Tools/Air/331/bin/adt -package -storetype pkcs12 -keystore cert/GPCAir.p12 -storepass fd -target bundle dist/FM application.xml -C bin
After this I receive java error:
unexpected failure: inputs not set
java.lang.IllegalStateException: inputs not set
at com.adobe.air.ApplicationPackager.createPackage(ApplicationPackager.java)
at com.adobe.air.nai.NativePackager.createPackage(NativePackager.java)
at com.adobe.air.ADT.parseArgsAndGo(ADT.java)
at com.adobe.air.ADT.run(ADT.java)
at com.adobe.air.ADT.main(ADT.java)
The java version I installed was the first one in the list: openjdk-11-jre-headless