Cannot find or complete the quest "[Stable] Register the Requested Mare" from the progression pass. I have finished all of the non-repeatable Vanacil stable keeper quest, according to the BDO codex this is supposed to be a black spirt quest but I cannot find it in both main and suggested lists from black spirt.

Seems like you already have a bunch of characters, so you probably have the quest already done, since its just once per family. If you have it done, you can talk to the black spirit and use the Chat interaction to complete this part of the progression pass

so you have to collect ur rewards at the top of the training progression pass page, it gives u the registered mare :3 its the first reward :3 Horse emblem requested mare