Setup nextcloud using my domain name from ionos in truenas core

I am new to all this so any help will be appreciated.

     I have my own domain from ionos web hosting. I am asking how would i go about setting it up. I have contacted ionos and they said they needed me to contact nextcloud and get the information on how to connect my ionos Domain to their platform. Thank you for your help

Seems you have got a domain at IONOS and not there a Nextcloud.

For subdomain cloud.yourdomain.tld maybe you set CNAME to a dyndns service for your router.

Post more details.

What other details do you need.