SSD

[K_G_Prajwal]

Does HP pavilion notebook 15au117tx come with an M.2 slot? If Yes, what type?

[Huffer]

Probably and I am sorry I cannot be more specific.

Service Manual

Start on p. 29 for instructions to remove the back cover. Inside you maybe see this:

Worst case scenario

If you are lucky you have this:

M.2 slot in red circle

If the slot is present it is a SATA only M.2 slot. So would use something like this:

https://www.amazon.in/Samsung-860-EVO-Internal-MZ-N6E250BW/dp/B07864V6CK/ref=sr_1_16?keywords=M.2+SS...

So open and inspect before you buy to be sure the M.2 slot is present as this model has had a lot of reports of its not being there as you can see in the first picture. The connection traces are there for an M.2 slot but the motherboard was made without the actual slot. 

Post back with any more questions and please accept as solution if this is the info you needed.