Hello Uday,
Thanks for your question
Based on this thread there is an issue in Developer SKU in the Bastion : https://learn.microsoft.com/en-us/answers/questions/2263387/azure-bastion-developer-sku-is-missing-in-the-supp
Please review the answers provided there for next steps.
The recommended work around as of now is to use Basic or Standard SKU
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola