09-18-2019 10:37 AM
You can check with compatible SSD for your system here (filter by Commodity type).
On S340-15IWL Laptop (ideapad) - Type 81N8 shows compatible parts up to 1TB PN 01FR510 (Storage SSD PM981 PCIe 1T SAM) along with 11 other substitutes available.
Other claims 2TB is also possible as posted here.
I hope this helps answer your query.