אני רוצה לשלוח להן הודעה עכשיו.

Usually, אני is helpful and often expected in the present tense.

Why? Because Hebrew present-tense forms do not clearly mark person the way past and future forms do. So רוצה by itself can mean something like:

• I want
• you want
• he wants
• she wants

depending on context and pronunciation.

So אני רוצה... is the normal clear way to say I want....
In casual speech or texting, people sometimes drop אני if the context is obvious, but the full sentence with אני is the safest and most standard.

Because unpointed Hebrew spelling often leaves out vowel differences.

So:

• a male speaker says אני רוצה = ani rotze
• a female speaker says אני רוצה = ani rotza

Same spelling, different pronunciation.

This is very common in Hebrew. Without vowel marks, masculine and feminine forms sometimes look identical in writing even when they sound different.

After רוצה (want), Hebrew normally uses an infinitive, just like English uses to + verb.

So:

• רוצה לשלוח = want to send

Here:

• רוצה = wants / want
• לשלוח = to send

The ל־ at the beginning of לשלוח is part of the infinitive form, not the word to in the sense of a recipient.

להן means to them or for them, referring to a feminine plural group.

So it is used when the recipients are all female.

Compare:

• להן = to them, feminine plural
• להם = to them, masculine plural or mixed-gender plural

So in this sentence, the speaker wants to send a message to those women/girls.

Because the women are the recipients, not the direct object being sent.

Hebrew treats send something to someone like this:

• לשלוח הודעה להן = to send a message to them

Here:

• הודעה is the thing being sent
• להן marks who receives it

אותן would be a direct object form meaning them. For example:

• אני רואה אותן = I see them

So English says send them a message, but Hebrew usually expresses that as send a message to them, using ל־.

Because את is used before a definite direct object, and הודעה here is indefinite: a message, not the message.

So:

• לשלוח הודעה = to send a message
• לשלוח את ההודעה = to send the message

That is why this sentence does not use את.

Literally, הודעה means message or notification.

In modern everyday Hebrew, it can often mean a text message, app message, or written message if the context makes that clear. So this sentence could naturally mean something like:

• send them a message
• send them a text
• send them a message now

If you need to be more specific, Hebrew can also use expressions like:

• הודעת טקסט = text message
• סמס = SMS/text

But הודעה by itself is very common and natural.

Yes, it can go elsewhere. Hebrew word order is fairly flexible.

This version:

• אני רוצה לשלוח להן הודעה עכשיו

is completely natural and neutral.

But you could also say:

• עכשיו אני רוצה לשלוח להן הודעה
• אני רוצה עכשיו לשלוח להן הודעה

These all mean roughly the same thing, but the emphasis shifts a little:

• עכשיו at the end often sounds neutral
• עכשיו at the beginning gives more focus to now
• placing it before לשלוח can emphasize the timing of the action a bit more

A common pronunciation would be:

• ani rotze lishloach lahen hoda'a akhshav
  if the speaker is male

• ani rotza lishloach lahen hoda'a akhshav
  if the speaker is female

A few notes:

• רוצה = rotze / rotza
• לשלוח = lishloach
• להן = lahen
• הודעה = hoda'a
• עכשיו = akhshav

If you want, you can think of the sentence structure as:

• I
  • want
    • to send
      • to them
        • a message
          • now