Hi,
I've published gentoo ebuilds for Enpass 6 on github: https://github.com/flbdx/enpass-overlay
It's currently up-to-date, but no promise for future releases :-)
If you want to monitor new releases from the official Debian repository, you can check the following URLS :
$ wget -q -O- 'https://apt.enpass.io/dists/stable/InRelease'|grep 'Date'
Date: Tue, 5 Mar 2019 13:55:15 UTC
$ wget -q -O- 'https://apt.enpass.io/dists/stable/main/binary-amd64/Packages' |grep Filename
Filename: pool/main/e/enpass/enpass_6.0.6.323_amd64.deb