Receiving Extradimensional Residence Permit - ExRP

Ever since the portals to other worlds started showing up, various beings wanted to move to new worlds. Sometimes they just want a cool new place to live, sometimes they want to escape from the rules of their world, and sometimes they want to move to a world safe from the influence of the Fae. The last one being more true ever since the Great Fae War has ended.
But moving to certain worlds, especially permanently is a very hard thing to do. Sometimes even getting a temporary (holiday) visa gets really complicated, especially for the species that tend to live way longer and whose holidays also last way longer.

Process of getting a permit

Paperwork

First, one needs to contact the government of the world they want to live in, a thing that is mostly done by contacting portal guardian first; This entails tons and tons of paperwork and waiting for a response can last years, which for some species could be generations. But if one gets lucky enough, they'll be invited for the second step to one of the neutral dimensions.

Studying and exams

Next, one has to go through the process of learning about the dimension they want to live in, its laws, and what's permitted morally there (no it isn't legal to kill someone just because they misspelled your name). Once someone thinks they are ready, they can take part in an exam, both theoretical and practical, that'll test their knowledge and their capability to adjust to the new world. For example, if species normally do something that is immoral in another world, there will be a challenge set up that will tempt them to do that multiple times, with increasing intensity.
But if someone manages to ace the test, there's only one last obstacle awaiting them.

Interview

As the last step, the one trying for the permit has to go through an interview with the inhabitants of the world they want to live in. They'll be asked the reason they want to move, they'll be checked if they are spies and if they are in any way dangerous.
If they manage to do well here, this is it. A completely new world will soon be open before them.

Ceremony

Depending on the number of successful applicants, the ceremony of handing the permit and welcoming new inhabitants of the dimension might be a more crowded or more personal event. Those parties are usually more elegant and more televised when a dimension is still "fresh" (the portals just opened) or if the new inhabitants are of some more exotic species.

During those parties, owners of the new ExRPs are introduced to the people who will help them adjust to their new lives and learn skills and knowledge used in daily life.