import Telnyx from 'telnyx';

const client = new Telnyx({
  apiKey: process.env['TELNYX_API_KEY'], // This is the default and can be omitted
});

const response = await client.ai.assistants.tags.add('assistant_id', { tag: 'tag' });

console.log(response.tags);

{
  "tags": [
    "<string>"
  ]
}