I used the catalog from photoshop elements to upload photos into lightroom classic. I added more photos to the elements organizer app, is there a way to sync the two to add the new photos or do I have to upload them from a different location to get them to appear?
Between PSE and LRC, it has to be one or the other. The only way to use both is to have separate collections in each. That is something like family photos in one and travel photos in the other. However, there's no reason for that if you like what you see in LRC more than you like what you see in PSE (or vise versa).
But trying to keep both going with the same images is not a good use of your time. I really suggest pick one.