Hi @TJ-Mughal , we have been able to do that with Salesforce flow. Let us know if you need help. In this case in the pic we are updating the LeadSource however we can also update ANY Lead / Contact field.
There are solutions available on the AppExchange like ZFusion that can automatically capture both the join & leave time for Webinars and Meetings into Salesforce . Once installed, data will automatically flow into Salesforce without any need for configuration.