Based on [vtsls schema](bd2df5a2d4/packages/service/configuration.schema.json (L1092)), experimental setting should be vtsls property not typescript.
```json
"vtsls.experimental.completion.enableServerSideFuzzyMatch": {
"default": false,
"type": "boolean",
"description": "Execute fuzzy match of completion items on server side. Enable this will help filter out useless completion items from tsserver."
},
```