Motherboard RAM limit for HP 14-dq1039wm?

[Phil3874]

What is the RAM limit for the motherboard in the 14-dq1039wm (8BD79UA#ABA) laptop?

There is only one RAM slow so I would like to know if it can be upgraded/what limitation the motherboard has? 
Any information on the motherboard would be appreciated. 

[banhien]

@Phil3874 

The specs of your machine is

         https://support.hp.com/au-en/document/c06450024

You can upgrade to 16GB or 32GB

   (a) 16GB: add same existing RAM to slot 2 or using the following compatible RAM

                    https://www.crucial.com/memory/ddr4/ct8g4sfra266/ct18584298

   (b) 32GB (max): install 2 x 16GB (one per slot) using the following compatible RAM

                   https://www.crucial.com/memory/ddr4/ct2k16g4sfd8266/ct16305291

Regards.

[Phil3874]

The specs of my laptop do not include any information about the motherboard, and the specs read as if is only one memory slot so I’m not confident in this answer. Perhaps the specs should make that clearer? 
There are two slots in this machine? Specs only indicate one. 

[Phil3874]

So, it appears there are two memory slots, this is not clear on the product specification page. 

Slot #1
Type Unknown
Size 8192 MBytes
Manufacturer Samsung
Max Bandwidth DDR4-2666 (1333 MHz)
Part Number M471A1K43CB1-CTD

The motherboard is a HP 86C8 (U3E1).

So, the manual reads: DDR4-2400 dual-channel support (DDR4-3200 bridge to 2666) so I think getting two DDR-3400 RAM cards, or one DDR-2400 are my options for RAM upgrades if I wanted to a higher speed on both RAM cards, or to just add a second of what is already there?