Create a PostgreSQL DB Server with Basic pricing tier by Geo-Restoring a PostgreSQL DB Server with General Purpose pricing tier

I get 1 Azure PostgreSQL DB servers: "DBServerA" under subscription "MySubscription" and resource group "MyResourceGroup". "DBServerA" has sku GP_Gen5_2 and its geoRedundant is enabled.

I would like to create a backup PostgreSQL DB servers "DBServerB" (from "DBServerA") which has sku B_Gen5_2 by following commands:
az account set --subscription MySubscription
az configure --defaults group=MyResourceGroup
az postgres server georestore --name "DBServerB" --source-server "DBServerA" --location westus --sku-name B_Gen5_2

These commands report error "cli.azure.cli.core.azclierror : Deployment failed. Correlation ID: XXX. The edition Basic is not a valid edition. Edition cannot be changed by restoring.
Deployment failed. Correlation ID: XXX. The edition Basic is not a valid edition. Edition cannot be changed by restoring"

Does it mean that it's impossible to create a PostgreSQL DB servers with Basic pricing tier by geo-restoring a PostgreSQL DB servers with GP pricing tier directly? (I cannot find documentations mentioning this explicitly)

If yes, any workaround available?

The "DBServerB" would be moved to my testing subscription/resource group as the testing database server by other commands