toiawasemadoguti ga roguintuuti wo kakuninsuru.

It is read といあわせまどぐち.

This is a compound noun:

• 問い合わせ = inquiry / contact / question
• 窓口 = service counter / contact point / office handling something

So 問い合わせ窓口 usually means something like the inquiry desk, contact desk, or customer support contact point.

It does not have to mean a literal physical counter. In business Japanese, it often refers to the department or official contact channel responsible for handling inquiries.

Usually it refers to a role, office, desk, or department, not necessarily one specific person.

Depending on context, it could mean:

• a help desk
• a support team
• a customer service contact point
• the office in charge of inquiries

Japanese often uses this kind of noun even when English might prefer support staff or the support team.

が marks the subject of the sentence: the thing that performs the action.

So in this sentence:

• 問い合わせ窓口が = the inquiry desk / support contact point is the one that
• ログイン通知を確認する = checks the login notification

A native English speaker may wonder why this is not は. The short answer is:

• が presents the subject more neutrally or as the main piece of information
• は would make 問い合わせ窓口 the topic and may sound more contrastive or explanatory

For example:

• 問い合わせ窓口がログイン通知を確認する。
  = The inquiry desk checks the login notification.
  (neutral statement, or focusing on who does it)

• 問い合わせ窓口はログイン通知を確認する。
  = As for the inquiry desk, it checks the login notification.
  (topic-marking, possibly contrastive)

を marks the direct object of the verb.

Here, the verb is 確認する, which means to check / confirm / verify. The thing being checked is ログイン通知.

So:

• ログイン通知を確認する = to check the login notification

This is a very common pattern:

• 書類を確認する = check documents
• 内容を確認する = confirm the contents
• メールを確認する = check email

Yes, here it functions as a single compound noun.

It is made of:

• ログイン = login
• 通知 = notice / notification

Together, ログイン通知 means login notification or notification about a login.

Japanese very often combines nouns like this without using words like of, about, or related to. So English learners should get used to noun + noun combinations such as:

• 会議資料 = meeting materials
• 登録情報 = registration information
• ログイン履歴 = login history

確認する is the dictionary/plain form of the verb.

This form is commonly used in:

• textbook example sentences
• written procedures
• labels or system descriptions
• casual plain-style writing
• sentence fragments in documentation

If you wanted a polite standalone sentence, you could say:

• 問い合わせ窓口がログイン通知を確認します。

So the choice of 確認する does not change the basic meaning; it mainly changes the style/register.

The structure is:

[subject] が [object] を [verb]

So here:

• 問い合わせ窓口 = subject
• が = subject marker
• ログイン通知 = object
• を = object marker
• 確認する = verb

This is a very standard Japanese pattern. Since Japanese is usually SOV (subject-object-verb), the verb comes at the end.

Japanese normally does not use articles like a or the, and it often does not mark plural explicitly.

So 問い合わせ窓口 could mean:

• the inquiry desk
• an inquiry desk
• the support contact point

And ログイン通知 could mean:

• the login notification
• a login notification
• login notifications

The exact interpretation depends on context.

English requires you to choose things like singular/plural and a/the, but Japanese often leaves that unstated unless it matters.

It can, depending on context, but not always.

At a basic level, が simply marks the subject. However, in some contexts it can imply this is the one that does it.

So this sentence could feel like:

• The inquiry desk is the one that checks the login notification

if the speaker is distinguishing it from some other department.

But without special context, it may just be a neutral description of a process.

Yes, it is grammatical and natural, especially in a formal or administrative context such as:

• workflow descriptions
• manuals
• system/process explanations
• business documentation

It sounds a bit formal and procedural, which matches the vocabulary:

• 問い合わせ窓口
• ログイン通知
• 確認する

In everyday conversation, a speaker might phrase the idea differently depending on the exact situation, but as a formal explanatory sentence, it works well.