As per following Microsoft document, Premium block blogs support both LRS and ZRS
https://learn.microsoft.com/en-us/azure/storage/common/storage-account-overview
1 more highly voted comment
EzBL▲ 17Highly votedFebruary 03, 2023 03:43 pm
key word "only" according to this link https://learn.microsoft.com/en-us/azure/storage/common/storage-account-overview ZRS is supported is some region not at all, then LRS would be the answer
https://learn.microsoft.com/en-us/azure/storage/common/storage-account-overview