My typescript compiler can't compile json key with camel case

Question

My dev tool: visual studio code & npm & powershell
My dev pc: Window 11
Here is the secnario I encountered
please notice the loginName in black background of vscode is camel case and the loginname in white background of chrome is lowercase
I just type npm run serve

After some digging,I still have no clue, I added lowercase key loginname into the Json, and below is its illusration

Please help me ,thank you ahead.