fix the following error:

0:1  error  This rule requires the `strictNullChecks` compiler option to be turned on to function correctly  @typescript-eslint/prefer-nullish-coalescing

tsconfig.json

@@ -20,6 +20,7 @@
     // Vitejs requirements https://vitejs.dev/guide/features.html#typescript-compiler-options
     "isolatedModules": true, // https://esbuild.github.io/content-types/#isolated-modules
     "useDefineForClassFields": true,
+    "strictNullChecks": true
   },
   "include": [
     "src/**/*",