Analyze feedback using AWS Comprehend and send it to a Mattermost channel

This workflow analyzes the sentiments of the feedback provided by users and sends them to a Mattermost channel. Typeform Trigger node: Whenever a user submits a response to the Typeform, the Typeform Trigger node will trigger the workflow. The node returns the response that the user has submitted in the form. AWS Comprehend node: This node analyses the sentiment of the response the user has provided and gives a score. IF node: The IF node uses the data provided by the AWS Comprehend node and checks if the sentiment is negative. If the sentiment is negative we get the result as true, otherwise false. Mattermost node: If the score is negative, the IF node returns true and the true branch of th

Help me set up the n8n workflow "Analyze feedback using AWS Comprehend and send it to a Mattermost channel" (https://n8n.io/workflows/965). It uses: Mattermost, AWS Comprehend. Import the template JSON into my n8n instance, list every credential I need to create, and walk me through testing it.