For DataSelf integration with your Acumatica (OData extraction and dashboard embedding), please give DataSelf an Acumatica user with the following roles:
Administrator
BI
Customizer
DashboardDesigner
ReportDesigner
Wiki Admin
Wiki Author
Be sure to set up the password to never expire.
You might add user roles to restrict the data access. For instance, adding a user role to only one of your branches will prevent DataSelf access to branches' data.