You can add a Facebook Page if your business already owns the Page; also, there is a chance to create a new page right from the Facebook Business Manager account.
Note that you must be an admin of that page to be able to add the page to the business manager. And, if you work for an agency, you should request your client’s Pages.
See also: How to Get My Facebook Page Verified
Below is a fast and straightforward way to add pages that are on your facebook.com on your business.facebook.com ad website.
Or You may want to see how to create a new Facebook Business Manager account from start to finish here.
Steps to Add Facebook Pages to Business.facebook.com
Step 1: Log on to www.business.facebook.com
Step 2: when you are in, click on the “Settings” icon. It is positioned at the top right of the page.
Step 3: then look at the left side of the menu and click on “Pages” under the Account menu.
Step 4: on clicking the “Add,” there is a popup to select from the options listed; to add a page or to request access to a page or to create a new page
So click on “Add a Page” to continue.
Step 5: You have the options to either type in the name of that page you want to add or the URL of the page.
If you prefer to type the name of the page, as you type, you see a list of pages you have that, then you can select from it also.
Then click on “Add Page” after you’ve inputted the information at the top.
Now, on the screen, you should see a confirmation that the page is successfully added on business.facebook.com
Now you should see the page on your list of pages added on www.business.facebook.com