Salesforce Connected App Certificate. You can use your own private key and certificate issued by a certification authority. The jwt is signed with the x509 certificate’s private key, and the connected app uses the certificate to verify the signature.

Configure a salesforce connected app. From your salesforce account, create a connected app.; The next step is to create a connected app that includes the certificate we just created.
Go to create > apps, click new in the connected apps area and create a connected app that enables oauth settings and uses the digital certificate d:\talend_certificate.crt you have downloaded.
A connected app is a framework that enables an external application to integrate with salesforce using apis and standard protocols, such as saml, oauth, and openid connect. Select use a domain specific issuer. Click download cert, as we will use this later. Create a connected app in salesforce.