Andrew, if your radio aggregator cannot supply them, here are the URLs of the main BBC stations available as 320kbs AAC. These are as at 01.01.2018 but I believe them to remain current.
I understand that access may be restricted to users with a UK internet address:
BBC Radio 1
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_one.m3u8
BBC Radio 1Xtra
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_1xtra.m3u8
BBC Radio 2
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_two.m3u8
BBC Radio 3
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_three.m3u8
BBC Radio 4
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_fourfm.m3u8
BBC Radio 4LW
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_fourlw.m3u8
BBC Radio 4 Extra
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_four_extra.m3u8
BBC Radio 5 Live
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_five_live.m3u8
BBC Radio 5 Live Sports Extra
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_five_live_sports_extra.m3u8
BBC Radio 6 Music
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_6music.m3u8
BBC Asian Network
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_asian_network.m3u8