Salesforce connected app plugin to add the AccountID to SAML attributes for community users

MyConnectedAppPlugin.cls

global class MyConnectedAppPlugin extends Auth.ConnectedAppPlugin {
    global override Map<String,String> customAttributes(Id userId, Id connectedAppId, Map<String,String>
        formulaDefinedAttributes, Auth.InvocationContext context) {
        // Get the user's associated contact
        User u = [SELECT Id, ContactId FROM User WHERE Id = :userId];
        if(u.ContactId != null){
            Contact c = [SELECT AccountId FROM Contact WHERE Id = :u.ContactId];
            // Add the AccountId to your custom attributes map
            formulaDefinedAttributes.put('organization_ids', c.AccountId);
        }

        formulaDefinedAttributes.put('salesforce_integration_id', 'SALESFORCE_INTEGRATION_ID');
        return formulaDefinedAttributes;
    }
}