If we were able to install and configure Mender Server Production installation and Raspbian ready for use image (2019-04-08-raspbian-stretch-lite-mender.zip), how can we generate TenantToken, to connect some Raspberry Pi devices to the server?
The TenantToken is only needed for Hosted Mender. For your production installation, the only thing you may need is the server certificate, if your server does not have a CA-signed cert.
OK. How the server certificate to be used in Raspberry Pi device?
Is this correct configuration for Raspberry Pi device?
What other settings are needed on the Raspberry Pi device to be able to connect to Production Mender Server?
If you are using a self-signed certificate on the server (ie not a CA-signed one) then you need to include it in your target image
More details are here: https://docs.mender.io/2.0/administration/certificates-and-keys#mender-client