Hello Aditi , Hope doing well and Welcome to MS Q&A
Cost Management budgets are not supported for Free Trial subscriptions in Azure. This limitation is due to the nature of the Free Trial subscription, which is designed to provide limited access to Azure services for evaluation purposes. To use Cost Management budgets, you would need to upgrade your subscription to a Pay-As-You-Go or other paid subscription type.
References:
- Azure subscription and service limits, quotas, and constraints
- Subscription considerations and recommendations
Please let us know if any further questions
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Thanks
Deepanshu