TS7016: Could not find a declaration file. And I can't add it

Question

I need to work with ssl-validator ssl-validator in my nodeJs(typescript) project - to validate ssl certificate uploaded by user. The library doesn't have index.d.ts file and I have to add it if I understood this principle correct. My file structure:

├── package-lock.json
├── package.json
├── index.ts
├── tsconfig.json
└── typings
    └── sslValidator.d.ts

index.ts:

import * as sslValidator from 'ssl-validator';
const { validateSSLCert, isValidSSL } = sslValidator;

const  main = async () => {
    const result = await isValidSSL(
        "-----BEGIN CERTIFICATE-----\n" +
        <CERTIFICATE>
        "-----END CERTIFICATE-----"
    );
    return result;
}

main();

sslValidator.d.ts:

declare module 'ssl-validator' {
    function isValidSSL (certificate: string): Promise<boolean>;
    function validateSSLCert (certificate: string): Promise<any>;
}

tsconfig.json:

{
  "compilerOptions": {
    "module": "commonjs",
    "target": "ES2017",
    "noImplicitAny": true,
    "strictNullChecks": false,
    "lib": ["es2017", "dom", "esnext.asynciterable"],
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "outDir": "dist",
    "baseUrl": ".",
    "sourceMap": true,
    "typeRoots": ["typings"],
    "traceResolution": false
  },
  "include": ["*/*.ts"],
}

Static code analysis doesn't underline anything, but after running I get:

index_t.ts:1:31 - error TS7016: Could not find a declaration file for module 'ssl-validator'. '/Users/nikita/Desktop/code/aws_sandbox/node_modules/ssl-validator/lib/index.js' implicitly has an 'any' type.
  Try `npm i --save-dev @types/ssl-validator` if it exists or add a new declaration (.d.ts) file containing `declare module 'ssl-validator';`

1 import * as sslValidator from 'ssl-validator';
                                ~~~~~~~~~~~~~~~

What do I do wrongly?

p.s. Is there any alternative of ssl-validator with typing in library?