Where is my (gtag) category and label data?

I’m pushing custom events into Google Analytics 4 with https://www.googletagmanager.com/gtag/js?id={GID}.

I’ve checked that my action, category and label variables are generating the strings I need:

window.gtag('event', action, {     'event_category' : category,     'event_label' : label }); 

…and my named actions are landing in my Google Analytics reports, but I can’t see any reference anywhere to my category or label data.

The last time I did something like this was with ga.js so although I’m not familiar with the latest Analytics reporting UI with regard to events, I am at least familiar with where and how to go hunting for the category and label data.

My category string is a 4 digit integer. My label string is stringified JSON, typically of around 250 to 300 characters, so well within the 500 bytes limit of a label datum.

But I can’t see it. Where might I be going wrong?