Alphanumerical number range for a sales order is not possible

[SAPSupport]

We need to use an alphanumerical number range for our sales orders but the external flag in the following SSCUI is not editable:

 > 102819 Define Number Ranges For Sales Documents

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[SAPSupport · Accepted solution]

It is not possible to set the external flag for new number ranges, the flag is read only. 

Please check the following documentation which will provide you with a solution:

https://help.sap.com/docs/SAP_S4HANA_CLOUD/a376cd9ea00d476b96f18dea1247e6a5/a01254bea38949bba7d5835f...