Unable to create meeting via Web API

I tried to create a meeting using client.join() endpoint and used the generateSignature script mentioned in Documentation to generate signature that consumes SDK Credentials ( SDK Key and SDK Secret) and gets passed to client.join() but I am getting this error

{type: ‘JOIN_MEETING_FAILED’, reason: ‘This account does not exist or does not belong to you’, errorCode: 200}

(Files are uploaded in the drive : Screenshot - Google Drive)
Refer Screenshot1 & Screenshot3 for code

My app is also activated,

Refer Screenshot2

Please help

@surbhi.arora Here are the sessions regarding WebSDK Integrations