Errors/Warnings in Article run through Data markup tool

I’ve added some schema markup to https://www.bi-lingua.co.uk and everything is fine except:

A value for the author field is required.
A value for the headline field is required.
A value for the image field is required.
A value for the publisher field is required.
The dateModified field is recommended. Please provide a value if available.
The mainEntityOfPage field is recommended. Please provide a value if available.

Could you point me in the direction to resolve please?

Thanks in advance