[Answer]-I want change directory and run command in fabric

As per the official tutorial, the error specifies that you have not specified a connection in your fabfile for it to deploy. Please check here.

Other than that, in the cd method(used along side the with statement), use full path like

with cd('/path/to/directory/myApp')

rather than just the ‘myApp’. Even if it is just ‘/myApp’. It improves readability and also makes sure that that is the path you wish to go.