It was legislated under PSD2, although from my understanding there may be certain exemptions in place from September 2019. I believe it will also depend on the individual member states as to how and when this will be enforced. I’ll try to get some more clarification on this form my colleagues.
All the banks we supported on the Chrome extension are part of the Open Banking CMA-9. PSD2 aside, It wasn’t a good use of our resources offering continued support for these Chrome feeds, they take a lot of time to fix when things change with the online banking interface.