Adding device variables to the HTTP integration endpoint as query string

I’m working with an IoT project. The end-application is a Fiware IoT platform and the integration with the ChirpStack application server is made by an HTTP endpoint URL. The problem is that, in order to make Fiware responsive to any device, the Fiware API needs to specify the DeviceId parameter in the URL query string. So, I’ve been using the ChirpStack Device → Config → Variables in order to customize the DeviceId variable for every device connected to the application. But I do not know how to make use of the variable in the HTTP endpoint URL… I’ve tried with $DeviceId, #DeviceId and others but nothing seems to be working. Is this possible? Any suggestion?
Thanks in advance!

This is not possible (currently).

Then, do we have to create as many different applications as devices in order to use the Fiware API? There is no other way? I mean, several different devices working and using the same integrations solution.
Thanks in advance

Unsure if it helps - I had to remove the ?event=up tag in the URL and all the advice was to manipulate externally. After some investigating and a bit of crash Python it was actually rather easy to have packets sent via the HTTP integration to a listening Python script that created the packet I wanted and then sent it on to the final destination. Might work for you too?

I don’t have experience with the Fiware API. If this is required, them maybe this could be added as a new feature in a future release. Or if required, it could be supported as a dedicated integration.