... was a cryptic message I received in my dream this morning. Apart from that, someone told me "you have finally accepted me into your kingdom", and I replied "No, I didn't."

First of all, why 4 centuries and 93 years, why simply not 493 years? Maybe centuries don't really mean that here. Is it the year 2513? Or maybe the 4 "centuries" actually mean "ages" and represent Prehistory, Ancient history, Middle ages and Modern period. In that case, have the aliens already visited in the Year 93 of the modern history? It's now a bit vague, so I'm not sure what year it could be.

And what kingdom? The Earth, or everything else apart from the Earth? Would the extraterrestrial beings tell us "no, we did not accept you", or vice versa?

Funny coincidence I came across when I searched the year 2513: Friday the 13th is in March and November, just like in 2020. But I don't know how common that actually is, so maybe it means nothing.

I don't know. This post is all over the place, but it's not the first time I had a vaguely prophetic dream and I can't stop thinking about it.