On the BBC Web site
BBC Parliament schedule page for October 21st NOW have an link saying "View HD" when you press on it the schedule page appear for BBC Parliament HD
https://www.bbc.co.uk/schedules/p00fzl73/2021/10/21
Also BBC ALBA schedule page for October 21st NOW have an link saying "View HD" when you press on it the schedule page appear for BBC ALBA HD
https://www.bbc.co.uk/schedules/p00fzl67/2021/10/21