Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello Atchaya Prabhu, thanks for posting this in our community.
The Microsoft Fabric trial is tied to your identity's GUID in Microsoft's licensing system. If you've previously activated a trial, even under a different tenant, you're likely ineligible to start another one using the same identity.
In some cases, the tenant may be too new, as Microsoft enforces a cooling-off period that typically lasts around 90 days. It's also possible that self-service trials have been disabled by your organization's admin in the Power BI Admin Portal. Another reason could be that your tenant has already reached the limit for free trial capacities.
This might be also helpful, Microsoft Fabric trial entitlement
Hope this helps clarify the situation.
Kind regards,
John Oli