Your hosting service Hostinet setup cPanel with that plug-in. We can't know how exactly they configured that system. You will need to ask them.
The error talks about a TXT record not being found. Are you trying to get a wildcard cert? Because a DNS Challenge and TXT record are required for those. If you don't need a wildcard maybe it will use the HTTP Challenge and work better.
I didn't see any support info on Hostinet website for Let's Encrypt certs. The only place they mention "free" certs is for self-signed certs. They also offer several paid certs. They may not be very helpful to you trying to get free cert with that plug-in.
That cPanel plug-in was not developed by Let's Encrypt which is offered by the ISRG. It is just the name the plug-in uses to describe what kind of cert they are getting.
I realize this does not fix your problem but I hope it helps you understand it.