To acquire a dedicated Microsoft dial-in bridge number from either 431 or 343 area codes in Canada, you need to use the Teams admin center to request and assign a service number. A service number is a type of phone number that can handle hundreds of simultaneous calls and is used for services such as audio conferencing, auto attendants, and call queues. Here are the steps to follow:

Sign in to the Teams admin center with your Microsoft 365 username and password1.

In the left navigation, go to Voice > Phone numbers.

Click Add (+) and then select New service numbers.

In the New service numbers pane, select the country or region as Canada, the number type as Toll or Toll-free, and the location as Manitoba (for 431 area code) or Ontario (for 343 area code).

Enter the quantity of numbers that you need and then click Next.

Review your order details and then click Submit request.

Wait for an email confirmation that your request has been processed. This may take up to 24 hours.

After you receive the confirmation email, go back to the Teams admin center and click Refresh on the Phone numbers page. You should see the new service numbers that you requested.

To assign a service number to your audio conferencing bridge, go to Meetings > Conference bridges and then click Edit next to Default toll or toll-free number.

In the Edit default toll or toll-free number pane, select one of the new service numbers that you acquired from the drop-down menu and then click Apply.

Now, you have acquired and assigned a dedicated Microsoft dial-in bridge number from either 431 or 343 area codes in Canada.