Type Error using ajv-formats with ajv v8.11.0

I have a typescript project and am following instructions to add "date-time" as follows:

```
let ajv = new Ajv({ allErrors: true});
addFormats(ajv, ["date-time"]);
```

but getting the following error for "ajv", the first argument to addFormats:
`Type 'Ajv' is missing the following properties from type 'Ajv': opts, logger, scope, schemas, and 17 more.`

My tsconfig is as follows:
```
{
"compilerOptions": {
"module": "CommonJS",
"target": "ES2020",
"noImplicitAny": true,
"preserveConstEnums": true,
"outDir": "./build",
"sourceMap": true,
"esModuleInterop": true,
"resolveJsonModule": true,
"moduleResolution": "node"
},
"exclude": ["node_modules"],
"include": ["my-project/src/**/*", "docs/**/*.json"]
}
```

The only way I was able to get it working was by initializing ajv as 'any' type, which doesn't seem ideal. Any ideas as to what could be the issue?