If I automatically change focus, will it break an accessibility standard

I am working on a Two Factor Authentication page.

A tester has suggested that after clicking the 'Send Token' button (Sends the token to the user's phone), we should automatically change focus to the token input field.

Now, my understanding is that the focus should not change automatically, at least not without a warning.

However, I think that the idea of moving the focus to the next action, is actually a good ui design, that helps the user follow the process, and saves them one click.

Is this practice ok with W3C accessibility standards? Are there any conditions that would allow me to change the focus?