If you’re using a Facebook business account it is easy to add user to manage your Facebook page or your AD campaigns.
You can also assure that your account is secured because you can assign to them an access level and all you need is their email address.
Ok let’s begin.
On your Business Account Dashboard click Settings
Then Click Add New Person
Add the email address
Just choose Ad as Business Manager employee
Then click Add People
Select what Page he/she is assign, just tick the box
You can change the role or access level
Then click next
Then assign an account, tick the check box
You can also choose what role or access level
Add you will receive this message just click close
And you will see this
Inform the user to accept the invitation and he/she can now access your business page.
Hope it helps.