Welcome to the Q&A Forum

thank you for your answer.

unfortunately, if i remove protocol, it is still not working..

Hello.
When I try to use 'On Page Grader' on specific site, I get an error message.

"
Page Optimization Error
There was a problem loading this page. Please make sure the page is loading properly and that our user-agent, rogerbot, is not blocked from accessing this page.
"
example : https://www.livedigm.com

Site's robots.txt settings are good. and I think there's no blocking factor. But On Page Grader cannot crawl the sites.
But campaign crawler is working well on the site. only On Page Grader is not working..

What should I change my server's setting or site's setting for crawling site on my site?
I'm using wordpress on cloudways / Digitalocean(singapore) server.

Thank you.