Monoprice sells a USB-C male to micro USB male 0.5ft cable https://www.monoprice.com/product?p_id=14957 . I've seen USB-C female to micro USB male adapters but haven't added any to my kit.

I have some usb micro female to usb-c male adapters which were "Benson tested" and don't come with a lanyard loop. I used some 3M vhb tape and thin flat elastic to make a leash. Tie a loop on one end of the elastic, slide over adapter, stick a thin cut of VHB tape under it to keep the elastic on, and tie the other end of the elastic to the cable.

A SoundCozy or LightningCozy might work https://cozy-industries.com/products/sound-cozy if you want something which looks nicer or some thin string through a Nite Ize Cord Collar https://www.niteize.com/product/Cord...Protection.asp