How to set up the NTP server in run time?

In the BALENA OS description, we should set up the NTP servers in the containers configuration or also using the environment variable, but all in all is not very clear if I need to chenge the NTP server in run time.
Our device is always configured at the moment of installation and most of the clients have their own NTP server.

Which is the best way to set up the NTP server in runtime?

The devices should pick up the NTP servers advertised by DHCP when connecting.
There is no other way to set NTP servers at runtime for now.
There is an open issue for that:

Thanks there, hope you get a solution soon