copy apple notes

Hello

I need to copy ALL of my many apple notes from one mackbook to another.

Both had El Capitan OS now one of them has High Sierra

I used to go to finder copy the physical file ( in /Group Container/Apple.notes ) to a flash memory and paste it to other Apple. Now I do the same but it does not show up. Is it because of OS difference? Can you please tell me what I have to do? It is urgent kind of.

Regards

Frank