Log into Your Facebook Business Page
Start by logging into your Facebook business page. You will then be taken to the page’s profile page.
Click on Settings
In the top right corner of your page, click on the Settings button.
Select Page Roles
Once you are in the Settings page, click on the Page Roles section in the left-hand column.
Add an Admin
To add an admin to your page, type in the name or email address of the person you would like to add as an admin in the Assign a New Page Role box. Once you have found the person’s name, click on the drop-down menu and select Admin. You can also add additional roles such as Editor, Moderator, or Analyst.
Click Save Changes
Once you have added the admin to your page, click the Save Changes button to save the changes.
Congratulations! You have now successfully added an admin to your Facebook business page.