Why they say #### SSL certificate error: The provider encountered an error verifying the DNS settings of your domain name. Please double check your nameserver settings and try again later.
Error detail: No TXT record found at _acme-challenge.***.dpdns.org
I’m assuming from this that you have a custom domain?
is your name server pointed to: ns1.infinityfree.com and ns2.infinityfree.com?
Are you using a service like cloudflare that could be getting in the way?