The NPC from which you can unlock the heist mechanic has not appeared.

Hi,
After obtaining the rogue's marks, the mission related to adding a map/city to the heist mechanics was unlocked, but there was no character to whom these tokens could be shown.

https://imgur.com/a/ng39LnO

If you have a rogue marker, you just click on it to open a portal to the Rogue Harbor.

Note that this expends 1 marker, but they drop in fairly large quantities, so it's not an issue that you have to spend one when you want to go there.