See orijin for MediaWiki:Api-help-authmanager-general-usage

The general procedure to use this module is:
# Fetch the fields available from <kbd>[[Special:ApiHelp/query+authmanagerinfo|action=query&meta=authmanagerinfo]]</kbd> with <kbd>amirequestsfor=$4</kbd>, and a <kbd>$5</kbd> token from <kbd>[[Special:ApiHelp/query+tokens|action=query&meta=tokens]]</kbd>.
# Present the fields to the user, and obtain their submission.
# Post to this module, supplying <var>$1returnurl</var> and any relevant fields.
# Check the <samp>status</samp> in the response.
#* If you received <samp>PASS</samp> or <samp>FAIL</samp>, you're done. The operation either succeeded or it didn't.
#* If you received <samp>UI</samp>, present the new fields to the user and obtain their submission. Then post to this module with <var>$1continue</var> and the relevant fields set, and repeat step 4.
#* If you received <samp>REDIRECT</samp>, direct the user to the <samp>redirecttarget</samp> and wait for the return to <var>$1returnurl</var>. Then post to this module with <var>$1continue</var> and any fields passed to the return URL, and repeat step 4.
#* If you received <samp>RESTART</samp>, that means the authentication worked but we don't have a linked user account. You might treat this as <samp>UI</samp> or as <samp>FAIL</samp>.