'IServiceCollection' does not contain a definition for 'AddGateway'

[Frikki]

On the demo branch, in Registration.cs in the Booking.Payments application, I experience the following error:

'IServiceCollection' does not contain a definition for 'AddGateway' and no accessible extension method 'AddGateway' accepting a first argument of type 'IServiceCollection' could be found (are you missing a using directive or an assembly reference?) Roslyn CS1061

Update 2023-08-24

I assume this is due to the changing nature of Eventuous alpha releases in flux.