To add an admin to an Instagram page, you must have a professional (business or creator) account linked to a Facebook Page, then use the Meta Business Suite or Facebook Page settings to invite a new person and assign them a role. You can add someone by their email address, and once they accept the invitation, they can manage the account according to the access level you set, such as "Admin" or "Editor".
Method 1: Using Meta Business Suite
This is often the most direct method for managing business accounts.
Go to business.facebook.com and log in.
In the left-hand menu, click Settings, then scroll down and click People.
Click the plus icon in the top right and select Add people.
Enter the email address of the person you want to add and click Next.
Choose their role (like "Admin" or "Editor") and grant them access to the specific assets, like the Instagram account.
Click Next and then Send invitation.