Tesco
etc are assessing requests for priority slots for the vulnerable. If you are
unable to go and use the early shopping hours set aside for family members to
shop for vulnerable customers (eg 9-10am at Tesco) because you too are
self-isolating, then you can phone their online shopping helplines
to register for a priority delivery slot if you already have an account
with them .(eg tesco is 0800 917 73590 and a Clubcard
account will suffice)
You can find out more Info at their websites
eg tesco.com/help/groceries-faq,
then click on COVID 19.