@Merabet Ponton, E Welcome to Microsoft Q&A Forum, Thank you for posting your query here!
Presently, SAS token can't be generated at the Folder level in Azure Storage Account.
Already Azure feedback on SAS token at folder level has been submitted, you can up-vote the idea, All the feedback you share in these forums will be monitored and reviewed by the Microsoft engineering teams responsible for building Azure.
Generating SAS at folder level is only supported for storage accounts with hierarchical namespace enabled ( i.e ADLS Gen 2 accounts)
In this article, you'll learn how to create user delegation, shared access signature (SAS) tokens, using the Azure portal or Azure Storage Explorer. User delegation SAS tokens are secured with Azure AD credentials. SAS tokens provide secure, delegated access to resources in your Azure storage account.
How Create SAS tokens for your storage containers
Please let us know if you have any further queries. I’m happy to assist you further.
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