Not allowed to add or modify item

Hello,

Next I am trying to modify a node with the session admin admin in the Javi code and I get the error trace:

javax.jcr.AccessDeniedException: /content/documents/santander/santander-developer/en_gb/content/producercontainers/common-apis/apicontainers/name-il.1.0/name-il.1.0/santanderbrxm:producerOrganizationContainer: not allowed to add or modify item

How can I get a session with permissions to write to the JCR repository? I have to do a content migration between environments and I need to write to the repository but I don’t know how to get the session correctly.

I am using importTask.createOrUpdateDocumentFromVariantContentNode

Thank you so much