Set Default PITR on Azure SQL Server Level

Petr_VM You can't set this at a server level, but you can create a custom Azure Policy to check for the desired value and enforce it if it's not set.

The policy below will look for the desired value and report if it's not set correctly. Change the effect to "modify" if you want it to automatically change the value to your requirements. Also change 4 to what ever you want the maximum value to be, it will audit for less than or equal to that value.

{
    "policyRule": {
        "if": {
            "allOf": [{
                    "field": "type",
                    "equals": "Microsoft.Sql/servers/databases/backupShortTermRetentionPolicies"
                },
                {
                    "field": "Microsoft.Sql/servers/databases/backupShortTermRetentionPolicies/retentionDays",
                    "lessOrEquals": 4
                }
            ]
        },
        "then": {
            "effect": "audit"
        }
    }
}