Hello Wawan,
Thank you for posting question on Microsoft Windows Forum!
Based on your query of any possibility of getting MAK key Windows standard edition after buying Windows server data center via CSP. When you purchase Windows Server Datacenter through the Cloud Solution Provider (CSP) program, you only receive Datacenter edition product keys. CSP might not provide Multiple Activation Keys (MAK) for Standard edition separately.
A Datacenter license legally allows you to run Standard edition workloads, but the activation keys provided through CSP are edition-specific. You cannot request a MAK key for Standard if you only purchased Datacenter. CSP does not support KMS activation. You must use the product keys provided in Partner Center, which are tied to the edition you purchased.
If you need Windows Server Standard. In this case, It is advisable to contact your CSP reseller or partner to provide the Standard SKU (and its MAK if MAK is the supported activation method for that SKU). They control issuance for your tenant.
You can consult the following article for more information regarding your concerns.
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