Using library item is like calling a function, you have to give it its input variables.
So you need to define our $_GET in your main action and also in your library action.
Then when you exec the library action, give as its input the $_GET input from the main action. So they value is passed.
Other way is just to include the library action then you don’t need to bind any parameters as it is just inline included. You still have to define the same $_GET parameter in both before usage.
so I’ve to define $_GET variable in both library and exec?
I ask you because I’ve defined $_PARAM in library
this is the test page:
https://www.campaniaturismo.org/test_room/test_api_action.php?id=8
it doesn’t run
I think its exactly as you did it?
This is how I got it to work:
Recording
This is error message by chrome. Unfortunately I can’t understand it
But it seems to be working on your test page?
Ok, now I see. Seems like there is a undefined variable for some reason:
Have you tried to make a new test project to see if its working then?
I see that you have an old version of appconnect:
The latest is:
Do you use latest version of Wappler, if you do. Try to upload all files to server.
Thank you very much. You are right. I’ve uploaded all the files and now everything is fine. How can I check app conncet version?
Recording-2
You are very welcome 
Great.
Now my page runs well but app connect is still 1,9,13 version.
How can I update it?
It should be automatically updated when you resave the page after a Wappler update. You could try delete the file and save the page again. Then it will be added with the new version.
Thank you very much indeed!!
I don’t want to disturb you but if you have a minute can you give a look to this other post:
It’s very strange but if I don’t find a solution I’ve to do my web site from the beginning again
No problem, will have a look.
