Bulk upload photos to activities

If you mean bulk upload of multiple photos for a single activity, then it is possible both on the phone app, and with GC Web - you can select up to 10 photos, and upload them at once, just as JohnfromPA wrote.

And if you mean uploading thousand photos without telling to which activity they belong, then no, it is not possible.

Hmm, maybe I wasn't clear enough in my question. I am looking for a script or a method to upload multiple photos to a specific activity, for many activities.

To be clearer, I have many photos with dates, and am looking for a way to upload these to an activity with the same date as the photo.

I have the activity id, the date for the activity, and the date for the photo.

As I said in the question, I'm aware that it is possible to do manually.

As I wrote, I do not think any such script exists, so you would have to code it yourself, or hire a coder to do it for you.