Couchbase Server 6.0.1 Enterprise Installation Problem

I am following for installation of couchbase server. I had installed the .deb package for Ubuntu 18.04 from the official website. But when I run ./bin/couchbase-server – -noinput -detached I get the message:
The maximum number of open files for the couchbase user is set too low.
It must be at least 70000.

Normally this can be increased by adding the following lines to

couchbase soft nofile
couchbase hard nofile

Where is greater than 70000. The procedure may be totally
different if you’re running so called “non-root/non-sudo install” or
if you’ve built Couchbase Server from source.

I have updated limits.conf file with:
couchbase soft nofile 70000
couchbase hard nofile 70000

Still, I am getting the same message.