Well, as both Belgium and Norway are eligible countries, it is quite OK for you to apply, just follow the call instructions. There is no big difference when applying as an individual compared to as a company/organisation. As an individual you will need to provide your unique national identification number, which in Belgium seem to be the: https://nl.wikipedia.org/wiki/Rijksregisternummer
If you intend to have partners in the experiment, you will also need to provide their respective individual or company/organisation identification number.
BR, /Jan-Olov, OrganiCity team