Do you always need an extra server to receive Webhook by using JWT

Hi I am trying to implement Auth0 to Ditto to authenticate.
In documentation they explain we need to have a server running to receive the JWT call and convert it to Formatted Ditto Auth Response.

My question is if this is a part managed by Auth0. Can we sent a Auth0 endpoint, and call that and manage all without and extra server running for this auth service? Since its an iOS app, its a pity if that’s needed.

Here the part I am talking about.

I checked a lot documentation, but on Ditto, Auth0 and Stack I couldn’t find out where to configure this in Auth0.