You can see a list of your SendGrid API keys via the "API Keys" section of your SendGrid account's "Settings" page. If you'd like to use an existing API key, you'll have to get this from whoever set up the key — SendGrid doesn't let you display API keys after they're created. If you want to create a new API key to use with Jet Admin, you can press the "Create API Key" button to create a new key and view it. Store it somewhere safe because SendGrid won't show it to you again!
To get your Secret Key, first sign up for a SendGrid account. Then you need to go to the API Keys settings to create your Secret Key. Set permissions for the Key API and click Create & View.
After you have successfully created the Key API, store it somewhere safe because SendGrid won't show it to you again.
Add SendGrid to an existing project or connect SendGrid as a resource when creating a new project. Copy your Secret API Key into the API Key field to connect the resource.