If you want to give permission only to view payments and make refunds, select Projects and Activities > My Projects and click on Project settings > Administration rights.
Next to Grant rights to another user, add the Unique number, or confirmed phone number, or confirmed email address of the person registered in Paysera and check the box by the rights you want to grant to this person. In this case, you have to select the following rights: View the list of payment gateway payments and Make refunds.
The person you are granting rights to, should have an identified Paysera account.