Adding ISBN to existing entry that has only ASIN

[Philippa]

I want to add the ISBN to this New Zealand published novel How to Stop a Heart from Beating. It has only the ASIN B0DM82R962; other information such as publisher and year are correct. I tried but cannot add the ISBN 9781869418618 (gleaned from several websites including New Zealand library catalogues). When I click on the ISBN-13 field I cannot add anything to it.
How can I do this? Thank you.

[Sandra]

You can't. Librarians can't. Possibly support may be able to, but I wouldn't bet on it.

If you want the isbn in the database, you'd need to add another edition. And the isbn 10 goes in the isbn field as well as the asin field.