Permissions of server created backups with linux

Hello, I am using a Urbackup server on a raspberry pi.
I have a problem with the file/folder permission of new backups.
The server creates new backups with the owner:group-> urbackup:urbackup
To access the files I added the default user to the group urbackup but the folder permissions are: drwx------
Because of this only the user urbackup has access to the files.
How can I change that, so that the urbackup server creates new folders with drwxr-x— and files -rwxr----- permissions, so all users in the group urbackup get read access to the backups?

It should give user+group permissions by default, but is affected by umask, I think. So maybe you can find a way to change the urbackup-server service umask?