dns "@" A-record for domain root [SOLVED]

[#1]

How do you enter an A record for the top of a domain on the Plusnet DNS tool?
Say I want to point "example.com" at 1.2.3.4, How do I do it?
I thought the convention was "@" for this but it isn't accepted by the tool. I've entered "." for it; is that right?
If not, what's the right way.

left @
type A
right 1.2.3.4

Thanks.

[#2]

Sorry, don't know what "." alone will give. However you could try entering example.com. in the left field (full stop after the domain name).

[#3]

A '.' won't work.
I think you can leave it blank. To be on the safe side though, enter yourdomain.tld. (with the qualifying dot at the end) like spraxyt's suggested.

[#4]

Thanks. Whilst waiting for the definitive answer I tried "example.com." (note the trailing dot) and waited for it to propagate. and that appears to have worked.