Hi @bangkok30182
According to the specifications for the laptop it has PCIe 3.0 (Gen 3).
Gen3 NVMe/Sata SSDs don't usually get hot enough, even under heavy loads, to require a heatsink as such. They come with a heat exchanger in the form of copper strips built into the sticker, which is usually enough.
Gen4 (PCIe 4.0) NVMe get very hot, especially when loaded down. So you will need a heatsink, but it will only run at Gen 3 speeds anyway in your laptop, so it might not get that hot but they come with a built in heatsink also.
Here's the maintenance and service guide that may help.
You could open the laptop and measure how much room there is on top of the SSD to fit a heatsink. See p.40 in the manual.
You will then have to find suitable heatsinks that may fit when the laptop is closed. Search online for SSD heatsinks.
How much ram is installed in the laptop? If the SSD is running hot it may be because there's not enough ram and the SSD has to work harder. The laptop supports up to 64GB of ram. See the specifications in the link above.
As to thermal paste, ifixit discourages recommendations as they can be too subjective and may be misconstrued as spam by the ifixit spam filter. It also creates problems in questions/answers with people linking spam websites with various products. Doing your own online research is probably best.