Create SalesOrderHeader texts to an existing SO in S4 Hana Cloud via CPI

I've a scenario wherein sales order header texts need to be created for an existing Sales Order(The header texts are absent in the SO as it was created by the SOAP-API(SALESORDERBULKREQUEST_IN) which does not have a provision for header texts). Now, when the header texts are attempted to be created via CPI using standard ODATA-API 'API_SALES_ORDER_SRV' & resource 'A_SalesOrderText', the following message is received - 'Creating operations are disabled for entity 'API_SALES_ORDER~A_SALESORDERTEXT'.

Would appreciate any pointers on whether this is possible via CPI and if so, the outline for getting this done.