How to register to a gateway without password

Hi guys;

Hi have a provider that only set up a username for me something like:

host =
user =
secret =

Now, my question is about how should i compose the registration string,
something like:

register => myusername:@provider-gateway ???

Note that there is no password (secret) on it.

Will it work?
What about security?

Thanks guys.

Solved. Thanks