Hi @Susie5 If you are using the All4 App Live Tv should be supported on the Tizen Platform,see some detail here https://www.channel4.com/4viewers/faqs/category/Live Tv
Alternatively if you have an aerial connected would be able to watch Channel 4,All 4,Film 4,E4 and some other channels via Freeview. Some information in this article https://www.channel4.com/4viewers/faqs/category/channels
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 5.0,Android 13 .