Files permissions in upload files on external storage

Hi, first of all, sorry for my english, I’m Spanish. Then, I have a little question, I try to install Nextcloud over my Freenas in a jail, the actual version in freenas is Nextcloud 10.0.1, and my FreeNas version is 11 update 4. Well, my user can access to an external storage via web and Android Phone, and I can work with it, but my problem is, when I make a folder or upload a file to the external storage, the permissions on the file are 755, with this permissions, when I go to the local computer, I can’t edit this files. It’s possible to change the default permission files in the NextCloud files uploaded?

Thanks for all, and sorry again for my english.