Replacement lens part number

We recently bought the QS-50 LiteMarker 50W Split Laser Engraver Fiber. When marking, there was a particular portion of the design that would repeadedly skip (need help on that too), but our first thought was to remove and inspect/clean the protective window and since it wasn’t retained in the screw-on ring, it fell and broke. It looks like it was 75mm dia based on the ring, and ~2mm thick. I’m not finding a replacement easily on the cloudray website or amazon. 1) anyone know the replacement p/n? 2) can we continue to use the marker until the replacement is identified and in-hand?
thank you,

Can you describe your problem in detail or have any pictures to illustrate it? In any case, it is not recommended to continue using the machine until the problem is solved.