aptly 1.4 - How to set Codename and Version with aptly?

[wpj2]

When switching from using aptly mirror to using http://gb.archive.ubuntu.com/ubuntu/dists/ we get N: Repository 'http://ubuntu-mirrors.internal.sanger.ac.uk/focal focal-updates InRelease' changed its 'Version' value from '20.04' to '' E: Repository 'http://ubuntu-mirrors.internal.sanger.ac.uk/focal focal-updates InRelease' changed its 'Codename' value from 'focal' to 'focal-updates' N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details. Do you want to accept these changes and continue updating from this repository? [y/N]

How can I specify the Codename and Version with aptly 1.4

Thanks, Pete Juhas

[spaceone]

Codename can be specified via Distribution, which sets Suite and Codename in the Release file.