How to use the pvtsutils.Convert.ToBase64 function in pvtsutils

public checkGenerateKeyParams(algorithm: RsaKeyGenParams) {
    // public exponent
    this.checkRequiredProperty(algorithm, "publicExponent");
    if (!(algorithm.publicExponent && algorithm.publicExponent instanceof Uint8Array)) {
      throw new TypeError("publicExponent: Missing or not a Uint8Array");
    }
    const publicExponent = Convert.ToBase64(algorithm.publicExponent);
    if (!(publicExponent === "Aw==" || publicExponent === "AQAB")) {
      throw new TypeError("publicExponent: Must be [3] or [1,0,1]");
    }

    // modulus length
    this.checkRequiredProperty(algorithm, "modulusLength");
    switch (algorithm.modulusLength) {
      case 1024:
      case 2048:
      case 4096:
        break;
      default:
        throw new TypeError("modulusLength: Must be 1024, 2048, or 4096");
    }
  }