How to link two instances with one being the primary for a landline?

[somebody-somewhere-over-the-rainbow]

I am trying to link a new machine to an existing signal-cli-rest-api instance that is registered as the primary machine for my landline. Does anybody know how to achieve this using signal-cli-rest-api ?

[somebody-somewhere-over-the-rainbow]

FYI - I was able to get it to work by using the native signal-cli inside the docker container on the new instance via signal-cli --config /home/.local/share/signal-cli link -n "optional device name" (as user signal-api) and then invoking the the REST API call on the primary machine /v1/devices/{number} with the sgnl://linkdevice?uuid=xxx as the uri string. As the config file is locked when signal-cli-rest-api is running. Jumping through these hoops is necessary as the rest api does not provide the ability to link without a qr code for now.