在加解密算法框架中使用HMAC 算法，采用SHA256，怎么传入自己生成的密钥去实现加密？

async function getHmac1(message:string){ 
 
  try { 
    let macAlgName = 'SHA256'; 
    let mac =cryptoFramework.createMac(macAlgName) 
    console.info("[Promise]: Mac algName is: " + mac.algName); 
    let arr = stringToUint8Array('12345678abcdefgh45623547895645548'); 
    let KeyBlob: cryptoFramework.DataBlob = {data:arr} 
    let symKeyGenerator = cryptoFramework.createSymKeyGenerator('HMAC'); 
    const symKey=await symKeyGenerator.convertKey(KeyBlob); 
    await mac.init(symKey) 
    await mac.update({data:stringToUint8Array(message)}); 
    let macOutpt= await mac.doFinal(); 
 
    const res=buffer.from(macOutpt.data).toString('hex'); 
    console.log(logPre + 'Hmac:'+res); 
  }catch (err){ 
    console.log('err:'+err) 
  } 
 
}