Keep in mind that neither the EtherScope nXG or LinkRrunner 10G do not natively support 100mb Fiber. The only path to 100BaseBX support can be accomplished by using a small media converter. These are available from various sources such as below:

https://www.networxproducts.com/fiber-media-converter-100base-bx-wdm-sc-30km-1310t-1550r

These are incredibly small and would connect to the ethernet port.