I have client script that will populate PO line item on fieldChange. Before i populate the line items, i would like to removeLine first, it works on Edit record, but not on New Record

var poLineCount = currentRec.getLineCount({
                    sublistId: 'item'
                });
                log.debug('poLineCount', poLineCount);
                for (var j = 0; j < poLineCount; j++) {
                    currentRec.selectLine({
                        sublistId: 'item',
                        line: 0
                    })
                    currentRec.removeLine({
                        sublistId: 'item',
                        line: 0
                    });
                }

SSS_INVALID_SUBLIST_OPERATION CurrentRecord.selectLine is my approach correct ? did i miss something thanks

You don't need to select the line first. Remove the lines in reverse.

for (let j = poLineCount - 1; j >= 0; j--) {removeLine...}

sorry i got type on the line, yes, it should be j instead of 0