NEED HELP in HMAC Validation

[Girish_Rajwani]

const hmac_header = req.get('X-Shopify-Hmac-Sha256');

const map = Object.assign({}, req.query);

delete map['hmac'];

const message = querystring.stringify(map);

const genHash = crypto

.createHmac('sha256', process.env.SHOPIFY_API_SECRET)

.update(JSON.stringify(message))

.digest('hex');

if(genHash === hmac_header){

Valid

} else {

Invalid request

}

but i am getting invalid request error

I followed below youtube video 

https://www.youtube.com/watch?v=D3iO4mZHgLk&t=2368s

in above video, they are comparing as 

if(genHash === hmac) 

but it should compare with hmac in the header send by Shopify, please correct me if i am wrong 

i tried above as well, and got below error

Received an error response (400 Bad Request) from Shopify:
If you report this error, please include this id:

Please help!

Thanks in advance 🙂