To use SendGrid for SMTP courier in Ory Kratos, you need to configure the SMTP settings in your Kratos configuration file. The error you're seeing indicates that the

connection_uri

property is missing in your configuration. Here's a general example of how to configure the SMTP settings in your Kratos configuration file:

yaml courier:    smtp:    connection_uri: <smtp://username:password@server:port/>

In your case, you would replace

username:password@server:port/

with your SendGrid SMTP settings. However, if you're using an API key for authentication, you might need to include it in the

connection_uri

in a specific way. Unfortunately, the provided extracts do not contain specific information on how to include an API key in the

connection_uri

for SMTP configuration. For more detailed information, you might want to refer back to the [Ory Kratos documentation](https://www.ory.sh/docs/kratos/emails-sms/sending-emails-smtp) or the SendGrid documentation.