Baz, it may be just the way the text under "On TB" has been worded
In the worst case scenario, provided you've got a TV licence, you can go to the BBC iPlayer TV Guide and change your location (at the right just above the row of dates) to a location which is showing it and watch it that way.
The Monday and Wednesday episodes appear to be restricted to England. The Friday episode appears to be absurdly restricted:
"BBC One except Northern Ireland, North East & Cumbria, Scotland, South, Wales & 1 more"