Adding new storage rasberry pi


I am installing nextcloud on a raspberry pi 4 with kali linux. First i installed nextcloud just on the sd card of the raspberr pi. Now i added a harddrive to the raspberry to use with nextcloud. I searched for some articles, but only could find a way to add external storage as local. It works, but i have setup nextcloud to use externaly. Unfortunatly it doesnt work external…

Could anyone help me finding a solution? Setting up the hdd as a main hdd for nextcloud, or adding it the way as external storage locally but really for external is both okay for me.

Thanks in advance!