Can I install additional SSD on my TravelMate P449-G2-M V1.09 ?

I have Intel Corporation SSDPEKKW256G7 256GB SSD in my laptop. I want to add another 256GB to it. Is it possible?

If possible, which gen of PCIe and slot should I buy? Will 2 ssd running will create pressure on my laptop/motherboard?

If not possible, then what type of SSD (what to say to the retailer) can I exchange my current ssd for? Will a 512GB ssd create pressure on my laptop/motherboard?

Here's the output of sudo lspci -vv | grep -E 'PCI bridge|LnkCap'

0:1c.0 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #6 (rev f1) (prog-if 00
[Normal decode])
               LnkCap: Port #6, Speed 8GT/s, Width x1, ASPM L1, Exit Latency L1 <16us
               LnkCap2: Supported Link Speeds: 2.5-8GT/s, Crosslink- Retimer- 2Retimers- DRS-
00:1d.0 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #9 (rev f1) (prog-if 00
[Normal decode])
               LnkCap: Port #9, Speed 8GT/s, Width x2, ASPM L1, Exit Latency L1 <16us
               LnkCap2: Supported Link Speeds: 2.5-8GT/s, Crosslink- Retimer- 2Retimers- DRS-
               LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L1, Exit Latency L1 <32us
               LnkCap: Port #0, Speed 8GT/s, Width x4, ASPM L1, Exit Latency L1 <8us
               LnkCap2: Supported Link Speeds: 2.5-8GT/s, Crosslink- Retimer- 2Retimers- DRS-