DDR5 RAM is not compatible with the 5520. You can increase the amount of DDR4 RAM you have though up to a total of 64GB. The service manual here has directions on RAM installation.
I bought a latitude 5520 with i7-1270P, but the RAM is DDR4. I would like to update the RAM to DDR5. Can I just buy a pair of RAM from eBay or Amazon to update it? Are they compatible? Or I must buy RAM from the DELL official site.
Can I update the RAM of Latitude 5520 by myself?