Hi Tibor,
In the IMA SDK, you can use the getTraffickingParameters() or the getTraffickingParametersString() methods of the
Ad object to retrieve any custom parameters associated to your ad. However, if you wish to add or send custom parameters via the IMA SDK, then, I'm afraid that this is currently not supported.
You may try and get in touch with your publisher on how you can configure your ad tags to contain custom data/parameters. I hope this helps.
Thanks and regards,
Peter Laurence N. Oliquino
IMA SDK Team