Hi Paul,
Just jumping on this thread as I am struggling with the same problem.
From your answer I am taking this to mean I should just be able to swap out the long static1.squarespace with my own domain? If so I don't think this is working...
For example - the long link is:
https://static1.squarespace.com/static/60a24248d1bdf007a7d6d14f/t/60d5e51a7a26701ad72cfce1/1624630555116/Model+Homeworking+Policy_HWW.pdf
If I change this to https://homeworkersww.org.uk/s/Model+Homeworking+Policy_HWW.pdf it doesn't work.
I am perhaps misunderstanding what you mean though or maybe there is a step I am missing out - any help appreciated.
Thanks,
Ishbel