Autoload error

Module 'Mageplaza_Core' from '/home/clients/7d8a2cee6a72cea27fd4ed69abbb5e37/web/app/code/Mageplaza/Core' has been already defined in '/home/clients/7d8a2cee6a72cea27fd4ed69abbb5e37/web/vendor/mageplaza/module-core'.