How to get pdfs onto iphone with a mac

I have a new iphone, and need to get all my work related PDFs into the phone as they are not copied across when you restore from an old phone.

I understand that books have been removed from itunes, although there is still a books tab in itunes when you browse the phone. One would expect to be able to drag and drop into this, but it doesnt work. Nothing is logical in itunes.

Googling, you have to use ibooks on the mac, and somehow sync.

ibooks on mac already has all the pdfs, but there is no menu, button or option to sync them with my phone. Ibooks on the mac seems to have no connection with the iphone.

In itunes, I have manually sync setup for music.

Here is the really weird thing. When I restored from an encrypted itunes backup, i got precisely one PDF on the phone (a docker user guide). in itunes when I open the phone tab and select books, it shows one book. However, this book is not on the phone.

Anyway, the crux is to find a way to get pdfs *(and books) from my mac to my phone.

Any ideas?