500 Internal Server Error on file upload

[kaszarobert]

Local banner cannot be created. It returns with this error message when I try to upload a JPG image.
2020/01/20 12:15:49 [crit] 10#10: *10 open() "/var/lib/nginx/tmp/client_body/0000000001" failed (13: Permission denied), client: 172.21.0.1, server: _, request: "POST /www/admin/banner-edit.php HTTP/1.1", host: "localhost:8080", referrer: "http://localhost:8080/www/admin/banner-edit.php?clientid=1&campaignid=1"

Is this a permission issue or something needs to be set up in the nginx config file?