Which driver to choose for GT 620M in Ubuntu 18.04?

I have an Acer Aspire E1-571G laptop with hybrid graphics (intel + nvidia optimus), with the recently installed Ubuntu operating system 18.04.2.
Linux 4.15.0-55-generic #60-Ubuntu SMP Tue Jul 2 18:22:20 UTC 2019 x86_64 GNU/Linux
I want to install proprietary drivers for Nvidia and use the video card using PRIME technology.
The tools in the operating system recommend installing the package nvidia-340:

:~$ ubuntu-drivers devices
== /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0 ==
modalias : pci:v000010DEd00001140sv00001025sd0000064Cbc03sc00i00
vendor   : NVIDIA Corporation
model    : GF117M [GeForce 610M/710M/810M/820M / GT 620M/625M/630M/720M] (GeForce GT 620M)
driver   : nvidia-340 - distro non-free recommended
driver   : xserver-xorg-video-nouveau - distro free builtin

But the native repositories have a newer driver nvidia-driver-390 https://packages.ubuntu.com/bionic-updates/nvidia-driver-390.
In the file README.TXT which is in this package, in the section "Appendix A. Supported NVIDIA GPU Products" there is my video card:

GeForce GT 620M 1140 1025 064C C

And I can't understand why I am not recommended to install a newer version, maybe there are some reasons for this?

Here is the information about the video cards:

:~$ lspci -knn | grep -EA2 'VGA|3D'
00:02.0 VGA compatible controller [0300]: Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09)
    Subsystem: Acer Incorporated [ALI] 3rd Gen Core processor Graphics Controller [1025:064b]
    Kernel driver in use: i915
--
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GF117M [GeForce 610M/710M/810M/820M / GT 620M/625M/630M/720M] [10de:1140] (rev a1)
    Subsystem: Acer Incorporated [ALI] GeForce GT 620M [1025:064c]
    Kernel driver in use: nouveau

What driver version do you recommend? install?
Thanks.