To add an admin to your Meta Business Page, follow these steps:
Go to your Meta Business Page and click on "Settings" in the top right corner.
Click on "Page Roles" in the left-hand menu.
In the "Assign a New Page Role" section, enter the name or email address of the person you want to add as an admin.
Select "Admin" as the Page Role.
Click "Add" to send the invitation to the person you want to add as an admin.
The person you invite will receive a notification that they have been invited to become an admin of your Meta Business Page. They will need to accept the invitation before they can access and manage the page. Once they accept the invitation, they will be able to make changes to the page, such as editing the page information, adding or removing other admins, and creating and managing posts.