Thankyou patience for the detailed explanation please look into the below solutions
Portal Updates or Feature Adjustments: Microsoft often updates features in the Azure portal, including the Preview Portal. The Terraform export option may have been temporarily disabled or reconfigured. This has been reported by other users recently, and Microsoft may be preparing updates related to this functionality
Some users have posted a query related to Terraform and Bicep that they cannot view this option when they export; please refer to their question below
Refer: https://learn.microsoft.com/en-us/answers/questions/2117601/azure-bicep-is-the-export-template-preview-feature
**
Alternate Solution: -
We have 2 solutions here.
1.Azure Terrafy – Import your existing Azure infrastructure into Terraform HCL
2.Terraform Import - Use the terraform import command to import existing infrastructure to Terraform state. The terraform import command can only import one resource at a time.
Refer: https://techcommunity.microsoft.com/discussions/microsoftlearn/importing-terraform-state-in-azure/3421289
Please let us know if you have any further queries. I’m happy to assist you further.
Please do not forget to "Accept the answer” wherever the information provided helps you, this can be beneficial to other community members.