How to combine the three-layer architecture with the unit of work in C#

I use three layer and Unit of work Design pattern together but project have credential bug!

data Read from database but does not save in it. Context Class Can't get changes and current transaction is null.

Current Transaction

architecture in the left of image

How can I fix this bug?

I create Repository in Data project(second image) and create Unit of Work in BLRazor project(second image) I test read data from database and correctly it work but add to database does not work correctly!!!