Do you miss to inform someone or fail to inform them? I am seeing miss appear in places but it just seems awkward.
"Misinform" is typically used to refer to an instance in which you provide incorrect information.
"Fail to inform" would refer to an instance in which you do not provide information at all.
A quick survey of Google results indicates that all uses of "miss to inform" are the result of what appears to be poor translation, which would be in keeping with my own observations — I've never heard the phrase used by a native speaker or in any context that wasn't garbled Engrish or equivalent.
When the verb "miss" takes a clausal complement, it is a gerund (form in -ing), not an infinitive.
So missed informing him is possible, though rather less likely than failed to inform him. But *missed to inform him is not something that a native English speaker would say.
The verb miss in this way has an implication that the person who missed it expected or planned for it to happen. So I missed informing him has a strong implication that this was something I specifically intended to do, but something happened to stop me; whereas I failed to inform him doesn't have that implication: I might have intended to, or I might never have intended to (though presumably somebody thought I would do so, or I wouldn't have occasion to say this!).