In Blynk IoT each device is represented by a separate tile on the front screen.
There isn’t (currently) a way to display data from one device on another device dashboard, or transfer data between devices.
There are some workarounds to this, such as sending data from one or more ‘slave’ devices to a single ‘master’ device using the HTTP(S) API.
The solution I use is to use Node-Red and MQTT. This way, Blynk only sees one device and Node-Red is used to aggregate and assemble data from multiple devices and this is sent to a single Blynk dashboard.
More info on this approach here:
Having previously used a local Blynk Legacy server I’ve made the move over to Blynk IoT, largely because the life of local server is limited. Removal of account creation from the app, and removal of the app from the App/Play stores has made life more difficult. The removal of “less secure apps” by Gmail has meant that emails from local server is no longer easily achievable. And, because the local server code isn’t being updated it will only be a matter of time before security vulnerabilities are an issue, and when Java 11 is retired then you’ll need to keep running the old (and vulnerable) version of Java to keep Blynk running.
For me, that level of inconvenience, potential vulnerability and uncertainty isn’t acceptable.
Pete.