# certificate based authentication

Navigation: Using TreeSize > Azure AD Configuration > # certificate based authentication |

If you want to use a certificate to allow TreeSize to identify itself to the authentication service, instead of using user-related login information, the following settings must be made:

1.first you need to create a self-signed certificate. To do so, please read here. You need to add the *.cer file created in the process to your app registration under Certificates & Secrets.You can then use the *.pfx file to log in via TreeSize.

2.Now add the Sites.Selected permission under API Permissions > Add Permission > SharePoint > Application Permissions. The shared site collections must be configured on your SharePoint beforehand. Please contact your SharePoint administrator for this purpose. You can find configuration help here.

## Problems with authentication

•If authentication is not possible despite a valid certificate, please make sure that claims-based (user-independent) authentication is supported by your SharePoint. Please also check that the site collections have been released correctly.