What should I use in my scenario signalr or worker service?

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BackgroundWorker

SignalR

I am building an application that closely resembles Google keep. The problem lies in the following scenario.(realtime sync)

Consider a user visits my website on 2 devices i.e laptop and desktop.
When he edits/adds/deletes any new Note then the other device should sync up immediately.
My backend is a .NET Web API project and front end is going to be a react.js project.

So I thought the following ways to do it.
1. SignalR basically used for Real time messaging, where it notifies any changes to my frontend.

2. Worker service, consider as soon as Login internally I will be calling worker service that will send a response as soon as there is a change in my database. A basic sceanario would be something like the following:

Step 1. User logs in using his/her account.
Step 2. As soon as I Login on other devices or the same device a worker service starts that keeps listening for any changes in my database.
Step 2. User presses "+" button to create a new note on first device.
Step 3. React frontend makes a call to My backend(Create API)
Step 4. React frontend makes use of UseEffect for the response and updates the UI.
Step 5. As soon 1st device makes a call for create API there is a change and then the second device gets the updated data.

there are 2 questions,
1.Is SignalR is a better way to do this? I might not need SignalR for other things.
While on the other hand, worker service might just suit a small project like mine? I don't know if its the right use case for me to use Worker service.

2. Can frontend be constantly be polling for info on any change in the database. Does useEffect work in the right context here?

Thanks

What I have tried:

Researched on worker service and SignalR but confused to decide which one to choose in my scenario.