Finding a way to test shopify theme locally

[IceCrew]

I'm currently developing a theme. I've linked the shopify theme to a github account so that I can develop it using my preferred IDE.
The problem is that I can't test my theme locally, I have to push the modifications to github and then look at the result on shopify preview tool.
So I installed shopifyCLI and noticed that this command could do what I wanted: shopify theme dev --store [storeId]
The problem is that I have absolutely no idea what to put in the "store" flag (a url? the shopId?). But which store, since I'm developing the theme locally)
Maybe I'm not on the right track at all, but I'd love your help 🙂

[RockTechnolabs]

Hello, @IceCrew 

In this case, you have to follow the below commands;
shopify theme dev --store=rocktechnolabs.myshopify.com

Once you run this command, In CMD it's showing to press any key for login in store notification. So just press the enter and you will be automatically redirect on browser and just login into your store. 
Once that done, in the CMD after the few seconds or minute you can see the local IP address for watch you theme. Please check attached screenshot.