How can I add my husband to this account so he can view also
Just have him sign into the same account if you want him to have access to everything you do.
That is what I do for my wife.
But remember, everything will say it has been done by you - even if it was done by him.
You may want to actually add him separately so you can see what he specifically does.
You can learn more about Shared Users, here.
How do I know if the shared user views an alert or history?