I'm trying to push terraform variable to vault using this recource

resource "vault_generic_secret" "secret" {
  path = "mxv/terraform/machines/test"

  data_json =  <<EOT
{
  "ip": "aws_instance.app_server.public_ip"
}
EOT
}

but in vault pushed variable name not value. Is there any way to push value from terraform to vault?