No, there is no way to add RAM to Microsoft Surface Laptops because the RAM is soldered into the Motherboard. Apart from that, upgrading the RAM on any Microsoft model requires opening the device which will void the warranty.
Microsoft has launched more than 20 Surface models and none of them can be upgraded in terms of RAM. To upgrade the RAM on a laptop, you should consider switching to another brand such as Dell, HP, MSI, or Lenovo.
I have used a Microsoft Surface Laptop 4 and it doesn’t have any RAM slot to add extra RAM. So, I looked at the internet for highest RAM in a Laptop and found it there’s a lot of laptop with 32 GB RAM to 128 GB of RAM for high end gaming and complex computing.