British passport citizen living in Sri Lanka

I am a British Citizen who has traveled to China on many occasions for business

I now live in Sri Lanka whilst I work as an expat for a Sri Lankan business.

I have been informed that when living in Sri Lanka, there is a new and specific requirement to applying for a visa? Is this correct?

In the past I have had an invitation letter form the business company in China and filled in an application form. Now I am told that I have to have an official stamp form the Chinese Bureau???

Please help advise,

Many thanks