First, go to the SurveyMonkey developer website (developer.surveymonkey.com, or developer.eu.surveymonkey.com if you are based in EU) and log in to your account.
Once you're logged in, click on the "My Apps" tab at the top. After that click on "Add a New App", and fill in the required fields, making sure to select Private App as the App Type.
Head over to the Settings tab in the SurveyMonkey website, and copy the Access token
On the "Settings" tab in the Deskpro App, enter the Access token.
While on the settings tab in the SurveyMonkey developer website, scroll down to scopes and set View Response Details, View Contacts, View Surveys, View Collectors, View Users, and View Responses to "Required", and click on Update Scopes.
Once you're happy with your settings, click the "Install" button to install the app.