Where Can I Find Official Information on the April 30 Visa Extension in Thailand?

Hi guys, does anyone know where I can get a screenshot of an official online article explaining the 30 April visa extension?

I'm in Thailand with my UK registered motorcycle and a visa valid until 20 April. The Temporary Import (TIP) i'm given at the border allows me to stay as long as my visa is valid.

Prachuap Khiri Khan Customs say that to extend my TIP I need a letter from Hua Hin Immigration saying there's an automatic extension. Hua Hin Immigration say they're not going to give a letter and to just print out an official document from online.

Any advice welcomed! Many thanks.