actor / people nfo local

[paulc]

EDIT: Disregard. You can also edit actors one actor at a time. Not sure where their data is held for easier editing.
Actor edit screen preview
   


Still leaving the below, even though I misread your post somehow.
You can manually add actors (People) one video at a time through the web http://localhost:8096/web/index.html#/metadata or whatever your server's URL is if you need to replace localhost, by selecting the video or media, and editing through the GUI screen or manually edit the nfo files. Below are four actors added to an episode of Two and a Half Men's NFO file I recorded OTA.

<actor>
    <name>Charlie Sheen</name>
    <role>Charlie Harper</role>
    <type>Actor</type>
    <sortorder>0</sortorder>
  </actor>
  <actor>
    <name>Jon Cryer</name>
    <role>Alan Harper</role>
    <type>Actor</type>
    <sortorder>1</sortorder>
  </actor>
  <actor>
    <name>Angus T. Jones</name>
    <role>Jake Harper</role>
    <type>Actor</type>
    <sortorder>2</sortorder>
  </actor>
  <actor>
    <name>Conchata Ferrell</name>
    <role>Berta</role>
    <type>Actor</type>
    <sortorder>3</sortorder>
  </actor>

Local .nfo metadata | Jellyfin

Sample NFO templates:  NFO files/Templates - Official Kodi Wiki