jsonwebtoken.sign() function doesn't accept process.expiresIn variable

I have a code snippet like following:

    const user_jwt = jwt.sign(
        {user_id : user_id.uuid},
        process.env.JWT_KEY as string,
        {
            expiresIn: process.env.JWT_EXPIRES_IN,
        },

    );

But I get the following error for the sign() method:

No overload matches this call.
  Overload 1 of 5, '(payload: string | object | Buffer<ArrayBufferLike>, secretOrPrivateKey: null, options?: (SignOptions & { algorithm: "none"; }) | undefined): string', gave the following error.
    Argument of type 'string' is not assignable to parameter of type 'null'.
  Overload 2 of 5, '(payload: string | object | Buffer<ArrayBufferLike>, secretOrPrivateKey: Buffer<ArrayBufferLike> | Secret | PrivateKeyInput | JsonWebKeyInput, options?: SignOptions | undefined): string', gave the following error.
    Type 'string' is not assignable to type 'number | StringValue | undefined'.
  Overload 3 of 5, '(payload: string | object | Buffer<ArrayBufferLike>, secretOrPrivateKey: Buffer<ArrayBufferLike> | Secret | PrivateKeyInput | JsonWebKeyInput, callback: SignCallback): void', gave the following error.
    Object literal may only specify known properties, and 'expiresIn' does not exist in type 

I have tried to edit it in different ways like

expiresIn: (process.env.JWT_EXPIRES_IN ?? "100d") as string,

or defining expiresIn separately like

const expiresIn = getEnvVar("JWT_EXPIRES_IN", "100d");

but none of them worked.

This code was working before I updated all my nodejs packages. And now it will work only if I hardcode it like expiresIn: "100d"

And this is inside my .env file:

JWT_EXPIRES_IN=100d

The type definition for expiresIn says:

expiresIn?: StringValue | number;

(recently started using types from ms)

So, you could do:

expiresIn: process.env.JWT_EXPIRES_IN as ms.StringValue; // or also: as unknown as number;

or assert the object as SignOptions:

{
    expiresIn: process.env.JWT_EXPIRES_IN,
} as SignOptions