I am using `jose4j` to encrypt a String with JWE, following this documentation <https://bitbucket.org/b_c/jose4j/wiki/JWE%20Examples>

In the example, they used `{\"kty\":\"oct\",\"k\":\"Fdh9u8rINxfivbrianbbVT1u232VQBZYKx1HGAGPt2I\"}`

It works well, but how to use RSA as kty ? Should I generate myself a key and put it in the "k" parameter ?