I'm trying to get pywikibot set up for the first time. It's on a Miraheze site and I'm getting this error when I try to log in:

-----------
WARNING: Non-JSON response received from server comprehensibleinputwiki:en for url
https://comprehensibleinput.miraheze.org/w/api.php
The server may be down.
Status code: 200

The text message is:

MediaWiki API help - Comprehensible Input Wiki
document.documentElement.className="client-js";RLCONF={"wgBreakFrames":true,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy","wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"7a406c0d0d1c2121406e444b","wgCSPNonce":false,"wgCanonicalNamespace":"Special","wgCanonicalSpecialPageName":"ApiHelp","wgNamespaceNumber":-1,"wgPageName":"Special:ApiHelp","wgTitle":"ApiHelp","wgCurRevisionId":0,"wgRevisionId":0,"wgArticleId":0,"wgIsArticle":false,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":[],"wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"Special:ApiHelp","wgRelevantArticleId":0,"wgIsProbablyEditable":false,"wgRelevantPageIsProbablyEditable":false,"wgVisualEditor":{"pageLanguageCode":"en","pageLanguageDir":"ltr","pageVariantFallbacks":"en"},"wgNoticeProject":"all",

...
------------

So it seems that it can access the page, but is not parsing it correctly for some reason. Anyone know what the issue is?