Matsumoto to Shinanoomachi booking

Hi we are going from Tokyo to Shinanoomachi on 14th October. I can book the Shinjuku to Matsumoto leg via JR east site but I am not able to find how to book the train from Matsumoto to Shinanoomachi on oito line. We will start our alone route from shinano omachi .

Can someone please help

That is because it is not possible to book the section from Matsumoto to Shinanoomachi (unless you want to take one of the rare limited express trains). Just hop on a local train - fully unreserved - to get there. Note that IC cards cannot be used at Shinanoomachi. So, you should either buy a base fare ticket all the way to Shinanoomachi. Or - if for some reason that is not possible - buy a paper ticket from Matsumoto to Shinanoomachi at Matsumoto Station.