iPhoto library to photos issues

I have an external hard drive with thousands of pictures on it. They are stored on the external in the old iPhoto library program.

we can’t look at them until they are in the new photo app.

issue is when I open photos and try to transfer it trying to love all picture to my computer.

is there anyway to transfer the old iPhoto library on my external to new photo app vi the external and not have to move them to my computer?

not sure if that makes sense.