Nextcloud SSO SAML environnement variable

I have a nextcloud (28.0.2) server linked to an LDAP directory with SAML application (6.1.1) I configured Apache2 like this:

<Virtualhost *:443>
<Directory "/path/to/file">

AuthType Kerberos
KrbAuthRealms DOMAIN
Krb5Keytab /etc/key.keytab
KrbMethodNegotiate On
KrbSaveCredentials On
KrbVerifyKDC On
KrbServiceName Any
KrbMethodK5Passwd On
KrbLocalUserMapping On
Require valid-user

In nextccloud logs i have “Error while trying to login using sso environment variable: Auto provisioning not allowed and user SAMACCOUNTNAME” does not exist".
I use the “REMOTE_USER” environment variable to log in to the user_saml application

When I try to log in via SSO to nextcloud, I get the message “Account not funded.
Your account is not funded, access to this service is therefore not possible."
When I log in manually I use “SAMACCOUNTNAME” it works

Do you have any idea why this isn’t working?

Thanks for your help