Enabling end-to-end TLS encryption can help keep data in-transit protected. In addition, using the latest version of TLS and modern ciphers can help keep data in-transit protected from man-in-the-middle and similar attacks.
In Azure Console -
In terraform -
References:
https://learn.microsoft.com/en-us/azure/application-gateway/end-to-end-ssl-portal
https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/application_gateway