Just add them back to your account. Note that if you deleted the domain the account was created with, you’ll need to move the domain’s file from /htdocs to <domain>/htdocs after adding it back in
if you removed them in this way, then the files remain (they will be just unlinked) as stated in the text
and you have to add the domains to the system again
it is useful to make a backup of all existing folders just in case before this action
then follow the instructions from GR9
and also probably wait a maximum of 72 hours for DNS propagation
If you deleted the domain root/document root (folders - carries your domain name
or if it is the first domain added then only htdocs) via FTP
then you have to recreate them again and upload all the files that were inside
and in that case, you should have a backup somewhere on your local computer in order to be able to do it and recover the deleted data.
I accidentally deleted subdomain and first creation domain, but now I got a second question, can I just delete the account, wait 20-60 days and then create a new account?