The UK government has set up two phonelines to assist people facing serious risk in Afghanistan. Read more on the UK government website.
Read the guidance in Pashto لارښود په پښتو ولولئ
Read the guidance in Dari راهنمایی به زبان دری
Below is the information that call handlers are requesting. 
British nationals, and family members of British nationals, in Afghanistan

Call +44 (0)1908 516666 and select the option “Consular services for British nationals”. The number is available 24/7.

Non-British nationals in Afghanistan
Call +44 (0)2475 389980. The number is available 24/7.

The following information is being requested when you get through:

Full name (as it appears on their passport/ID card). In the event they don’t have an ID card or passport (which is quite common), you just give the name as they prefer it to be spelt;
Contact details (telephone and/or email). Make sure it’s an Afghan direct contact number.
Date of birth;
C…