wp-json API: not logged in when clicking link to the API from admin mode

I needed to include the nonce in the URL. Solved it by adding ?_wpnonce=<?= wp_create_nonce( 'wp_rest' ); ?> to my URL. There is some info here, but I thought the nonuce wasn’t needed unless I tried to alter data, or something like that. That the WordPress authentication cookie would be enough.