Steps to share Facebook Business Manager Access Token & Facebook Pixel id -

1. Login to Facebook Business Manager

2. In the left navigation bar click on "Data Sources"

3.  Under Data Sources, Click on "Pixels"

4.  Click on "Open in Event Manager"

You'll be redirected to Event Manager page

5.  Click on "Settings"

6. Copy the Pixel ID

7.  Scroll down to "Generate Access Token" and generate the same.

8. Copy the Access token.

That is the process by which you can locate it. 

To provide you with additional guidance and support, We have attached a video. You will find step-by-step instructions and visual demonstrations that can assist you with the process.