How to use the jose.JWK.asKey function in jose

let key;

        if (header.typ !== 'dpop+jwt') {
          throw new Error('typ must be dpop+jwt');
        }
        if (typeof header.alg !== 'string' || !header.alg || header.alg === 'none' || header.alg.startsWith('HS')) {
          throw new Error('invalid alg');
        }
        if (!instance(provider).configuration('dPoPSigningAlgValues').includes(header.alg)) {
          throw new Error('unsupported alg');
        }
        if (typeof header.jwk !== 'object' || !header.jwk) {
          throw new Error('header must have a jwk');
        }
        try {
          key = JWK.asKey(header.jwk);
        } catch (err) {
          throw new Error('failed to import jwk');
        }
        if (key.type !== 'public') {
          throw new Error('jwk must be a public key');
        }
        if (typeof payload.jti !== 'string' || !payload.jti) {
          throw new Error('must have a jti string property');
        }
        if (typeof payload.iat !== 'number' || !payload.iat) {
          throw new Error('must have a iat number property');
        }
        if (payload.htm !== this.ctx.method) {
          throw new Error('htm mismatch');
        }
        if (payload.htu !== `${this.urlFor(this.route)}`) {

secret.forEach((secretString, i) => {
    const key = JWK.asKey(deriveKey(secretString));
    if (i === 0) {
      current = key;
    }
    keystore.add(key);
  });