Sending an ACME HTTP validation request to www.imagesvanuatu.com results in an unacceptable redirect. This is most likely a misconfiguration of your web server or your web application.
It appears that a redirect was generated by your web server that is missing a trailing slash after your domain name: https://imagesvanuatu.com.well-known/acme-challenge/letsdebug-test. Check your web server configuration and .htaccess for Redirect/RedirectMatch/RewriteRule.
Trace:
@0ms: Making a request to http://www.imagesvanuatu.com/.well-known/acme-challenge/letsdebug-test (using initial IP 13.210.87.234)
@0ms: Dialing 13.210.87.234
@566ms: Server response: HTTP 302 Found
@566ms: Received redirect to https://imagesvanuatu.com.well-known/acme-challenge/letsdebug-test
A test authorization for www.imagesvanuatu.com to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
Fetching https://imagesvanuatu.com.well-known/acme-challenge/xiASZDkSEQ_PD9xuU1WpSOMDx41hdHfEup92iigiyHs: Error getting validation data