In order to access BRM, you first need to be invited to a specific store.
You can't access BRM just by visiting the login page. (that is only for people who already have a BRM account) Each user is actually mapped to a home store, so the first step is to be invited to a specific store by your manager. This ensures that only the right people can access each store.
Ask your store manager to invite you. Be specific about which email address. You will receive an invite for that email address. Follow the instructions in that email.
It also means when you're added you don't need to worry about which store to visit, simply by logging in you will be directed to your store.
So please ask your store manager to add you to the store where you are working and that will automatically send you an invite to that specific store on BRM.
But wait - I don't have a store manager...
Then you might be wanting to try out your own BRM on a FREE trial.
See Also
how exactly does my manager add me to the store?
we are a multi-store operation - how can I switch between stores in my organisation?
problem-solving - are you using the wrong door?