How to implement Notifications and Backend for mobile app?

All kind time of day! I, as a developer inexperienced, need advice from knowledgeable and skilled representatives of iOS dev.
Doing now the app and there is a problem with the backend. Decided to choose for cloud storage data - Firebase. Yes, I heard about it many negative due to the lack of flexibility and compromise in everything and everyone, but decided to stay on it, because this is the fastest option in terms of implementation.
Note: I'm more on the frontend and backend hardly know, in Java can not and generally a quitter, only-Swift coder, hipsters, and other shit dev'and modern.
So, with the preservation and proper display of data in theory, no problems should arise. But, with regards to Notifications, everything is very blurry and unclear. I the project will require notification under the terms and there was nothing I could dig up on the Internet.
Explain with an example:
For example, I have different businesses that have different profile of someone is a mechanic, someone a plumber, someone electrician. They are all from different cities - someone from London, someone from Vancouver and someone from Bobruisk. And I have regular users who bought a variety of services. And that's what the user submits a General application for what he needs an electrician, and this user is located in Bobruisk. And when the user has applied, to all entrepreneurs-from Bobruisk electricians should receive a notification that there was an order, email the user and agree on the conditions. These notices must come in even when the app is turned off.
Also, in the future, to iOS it will be added and Android version. And later will website which will use the data.
And I have no idea how this can be properly implemented. Can someone advise something specific? Does it really make on Firebase? If so, how? If not, what are the analogues? Or, if to write the server, how and what do I need?
Immediately apologize for my stupidity, I'm still too green at this. Give a chance to young and stupid.
June 10th 19 at 16:14
1 answer
June 10th 19 at 16:16
And what You will not accept this option:
I read about the FCM, but haven't found a solution how to make notificatin sent to users on specific conditions. If you have a tutorial or a guide - I would be very grateful. - adonis_Kessl commented on June 10th 19 at 16:19
did not understand You. FCM is able to send to groups of users. How are You going to do, he does not know and does not want to know. You're the one that initiates the sending of the notification, sending a request to serev FCM with all the necessary data. 1*f-Ip3SdLA6ylHSf0gpgTnA.png
When you need to, then send a request to send a notification to your server. - alycia_Pfannerstill commented on June 10th 19 at 16:22
I mean, I don't really know how to initiate it. I have never seen the materials on how to submit a request to notificati came to users with specific data(location, personal characteristics, etc.). here is a little do not understand how it works. for example, how to send notifikasi particular user - I understand, let's say its id. but in firebase is filtering users to make some group on any parameter and to send them push can't find. in the head as it does not get the picture. - adonis_Kessl commented on June 10th 19 at 16:25
carefully re-read the Doc FCM. Starting from and ending ,

Topic Messaging is simply a subscription on the topic and send to all subscribers.
Device Group Messaging is messages to a single user who uses multiple devices for one account.

Your choice of Topic Messaging. Examples of topics: the Babruisk branch of electricians, London electricians, etc.) All electricians from Bobruisk subscribe to topic "of the Babruisk branch of electricians" and get notifikasi the arrival of new information in the topic.

All examples and even the console in order to check this without creating a backend there. Take a closer look. - alycia_Pfannerstill commented on June 10th 19 at 16:28
Thank! Now I will learn :)
Also found Firebase Cloud Functions is not an option for me. Was only in JS to understand. - adonis_Kessl commented on June 10th 19 at 16:31
Welcome! - alycia_Pfannerstill commented on June 10th 19 at 16:34
, Firebase Cloud Functions, but this is a good thing, sorry :) - alycia_Pfannerstill commented on June 10th 19 at 16:37

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