Hi,
the redirect_uri_mismatch normally comes from not following correctly point 5 and 6 of the documentation.
“5. Authorized JavaScript origins”: Enter the website address of your website without any sub-folders ex: ‘http://www.mysite.com/’
Note: match is exactly as your site, so if your site does not use WWW, leave it out.
“6. Authorized redirect URIs”: Enter your website address followed by the same specific URL ex: ‘http://www.mysite.com/wp-admin/admin-ajax.php?action=geodir_ga_callback’
Please delete that project and start over by adding the correct URL (with WWW in your case) to obtain new tokens.
Thank you
p.s. searching for redirect_uri_mismatch in the forum would have brought up several topics with this answer.