This endpoint adds one or more Applixure environments to the board's synchronized environments.
If board is configured to synchronize all of account's environments, those environments cannot be added using this endpoint. Only additional environment(s) with explicit credentials can be added in this case.
If board is configured to not synchronize all of account's environment, this endpoint must be used to manually add those account environments that should be synchronized from the account. For any such environments, no explicit credentials has to be first establish using /validate and /establish endpoints. For any other environments, not belonging to the account, a referece to the credentials established previously through /establish endpoint has to be present in the payload.