GET/POST API WEB doesn't work in different environments

User accounts are not part of a deployment package. You will have to create a new service account on the other environment and assign the necessary permissions to it. And use the new credentials for calling the APIs.

I've created this account but now the api web get me error 404. But the url it's the same copied from the api get web created in appian. Why?

I cannot say anything without knowing more about what you are doing ...

stackoverflow.com/.../how-to-ask

i guess i make a simple question: How can i assign the necessary permission to this account once created? Where i have to go on this application to do that? If you have to be ironic, go to another place 

This is not about irony! What kind of advice would give me when I say: "I am here in that city and I want to go shopping. Should I go left or right?"

That 404 has nothing to do with any permissions. But to answer your question, that account at least needs viewer permissions on the Web API object.

Simply create a service account in the environment in question and put them in the appropriate group that the API is secured to.

I usually create a dedicated group for API users and I'll secure the API using that group.

Thanks for the reply sir, now i've added an account into the service account group and i've added the service account group into the security level of the api web and set it as administrator. Now the api web it's triggered by the prompt but it doesn't show nothing, as shown in the picture below. Could you tell me why this is happen sir? Thanks for the reply. 

I suggest to NOT share any credentials to the public.

And to answer your question with another question, we do not know what the API should return. Can you help us?

And to answer your question with another question, we do not know what the API should return. Can you help us?