Hello @Maximiliano Gibert - Thanks for reaching out. In order to have Logic Apps workflow send emails using SendGrid, you will need to maintain an active account with SendGrid. I'll try to provide you with more elaborate instructions specifically for using SendGrid but for now, I'll share the following resources that might be of help:
- Tutorial: Send email and invoke other business processes from App Service
- While this tutorial uses the GMail for its action for sending emails, you can use the tutorial as a general example of such workflows and easily replace the GMail connector with the SendGrid connector.
- Send email with Logic app
- This sample uses the SendGrid connector and is a good example that you can leverage to build off of it.