Tourist L type...unable to apply in person as abroad?

Hi,
I am visiting China for tourism In January, 2018 for about 3 weeks. But 4 months before I go I will on a round the world tour and not going back to UK in that time and therefore not able to go into the Chinese Embassy in London to get my Visa for China. If I send them all the required documents can a friend or member of my family do it for me and then post it to whichever country I am in at the time.