About applications and connections
The use of any Event or Action card in a Flow requires a connection with a third-party application such as Salesforce or Gmail. To successfully run a Flow, each Event or Action card will have to have a set connection to the application to which it belongs. For example, the Create User card for Salesforce and the New Email Event card for Gmail will need a connection to the Salesforce and Gmail applications, respectively.
When first adding a card, you’ll be prompted to choose a connection. If you’ve already used a connection for the chosen application, that connection will be chosen by default. If any Options are required, you’ll also be prompted for those before you continue. The process of creating a connection depends on the application and the authorization type required by the service.
You can also create multiple connections for the same application (using different user accounts) or for multiple environments (such as test, staging, or production). These connections can be managed in the Workflows platform by going to Settings >> Connections.
Once you've selected a connection and options, you can edit them by clicking the name of the connection at the top of the card or by clicking Options just below that. If a connection is not working or any required options are missing, a red icon will show to the left of the name. A green check indicates the connection is healthy and all required options have been provided.