If you have got the the exception:
1 exception(s):
Exception #0 (Magento\Framework\Exception\LocalizedException): Please upgrade your database: Run "bin/magento setup:upgrade" from the Magento root directory.
The following modules are outdated:
Df_Backend schema: current version - 2.0.0, required version - 1.0.0
...
please execute the following SQL query (e.g. using phpMyAdmin):
update setup_module
set schema_version = '1.0.0', data_version = '1.0.0'
where
module like 'Df%'
and schema_version = '2.0.0'
and data_version = '2.0.0'
;