Hello Jose,
If you have chunk referenced using camera positions in the same coordinate system that were used for GCPs (markers), then you'll see imported markers in the same coordinate space and will be able to use Filter Photos by Marker option to adjust the proposed marker projections on the corresponding images. Otherwise you can use convert option in the Reference pane to get camera positions in the required coordinate system.
In case the cameras are not referenced, then you need to put at least two projections for at least three markers (using the same labels as in the text file), load marker coordinates from the file and then already put other projections on the photos.