why is my macbook pro not fitting properly in my 39 inch insignia TV?

i recently bought roku premiere 4k streaming device and i’m trying to mirror my macbook pro to use my tv as mirror monitors but the screen is not fitted properly in my TV, the edges are eaten up by the frame I see the apple symbol and time only half of that in the screen,

I tried changing my display settings in macbook optimized for my tv instead of laptop but still the same issue