When the Kaleyra connector is installed on LeadSquared, ideally, a custom menu should appear under "Apps" named "Kaleyra SMS Template." which is used to store the SMS templates for Kaleyra on LeadSquared.

Now since this is a custom menu item, there is a standing issue where this menu is not created even when the Kaleyra connector is configured correctly.

To resolve this, we have to install the connector "Custom Menu for Web App" on the account and then reinstall the connector again.

This works because the following API is being used by Kaleyra for creating this custom menu item: Custom menu for Web App

Now, this API calls for a connectorID which is the connector ID for the app "Custom Menu for Web App".
However, this ID changes once the app is installed and thus the app being installed is a requirement for the menu item to get created.
Also, the connector ID should not be taken from the URL but from the source code of that particular connector. (Inspect Element)

If it still doesn't work, you can create the menu item from the "try it" option of the API docs itself provided the connector is installed and the correct connector ID (from the source code) is used.