Your own link did, but now the page returns a 404 error.
However, see https://ico.org.uk/for-organisations/guide-to-data-protectio...
> Under the UK GDPR, you must appoint a DPO if:
> - you are a public authority or body (except for courts acting in their judicial capacity);
> - your core activities require large scale, regular and systematic monitoring of individuals (for example, online behaviour tracking); or
> - your core activities consist of large scale processing of special categories of data or data relating to criminal convictions and offences.