Photo Library is on an external drive not on my main computer

For some reason my Photos Library is on an external drive. I use this drive to free space on my main computer. This library is named Photos Library 2. It is not complete and seems to have stopped in April this year. All my photos are in iCloud though. I really want all photos on my Mac mini albeit optimised for storage. Should I delete the library on the external drive and download all photos from iCloud.com? Many thanks in advance for any help (which I hope won't be too technical). I'm on Sonoma 14.7

Gill