Discord OAuth2 is inoperative

When I attempt to authorize at /u/rokejulianlockhart/preferences/account, I see the undermentioned (albeit, originally unprettified):

<div class="wrapper_e1a4cf">
   <div class="header_e1a4cf headerFailure_e1a4cf"></div>
   <h2 class="defaultColor_a595eb heading-lg/bold_dc00ef defaultColor_e42ec6 text_e1a4cf" data-text-variant="heading-lg/bold">Invalid OAuth2 redirect_uri</h2>
</div>