Mint 19.3 64 bit Libre office doesnt get updated inspite of PPAs

Hello,
I have added LO PPAs but LO isnt getting updated to version 6.4. Is the PPA correct?

sudo apt install libreoffice
Reading package lists… Done
Building dependency tree
Reading state information… Done
libreoffice is already the newest version (1:6.3.4-0ubuntu0.18.04.1~lo2).
0 upgraded, 0 newly installed, 0 to remove and 29 not upgraded.
(base) uma@mint-18-uma ~ $ grep ^ /etc/apt/sources.list /etc/apt/sources.list.d/*|grep libre
/etc/apt/sources.list.d/libreoffice-ppa-bionic.list:deb http://ppa.launchpad.net/libreoffice/ppa/ubuntu bionic main
/etc/apt/sources.list.d/libreoffice-ppa-bionic.list:# deb-src http://ppa.launchpad.net/libreoffice/ppa/ubuntu bionic main

Just looks into the PPA: it’s not yet updated to 6.4. You should ask the PPA owners about their plans to update.