Quest \ "Diamond City Blues \" (Fallout 4)

Can't find the entrance to Marowski's lab. Where is he, in more detail, plz. This is the quest that begins at the bar, and the husband asks to go with him to deal with the bartender. Then, on the embankment, a gathering of gangsters. After that, enter Marovski's laboratory on the territory of the Trefoil fish factory. I took out the plant, climbed onto the roof - I also took out everyone. Where is the laboratory itself? The map shows that in the same place.