45 degree 2020 extrusion brace endcap for M6

My original plan was to use [this brace by Shift31](https://www.thingiverse.com/thing:2410086) and if I had ordered more extrusions from Misumi it would have worked. Instead I ordered [extrusions from Amazon](https://www.amazon.com/gp/product/B07459NK2Y/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1) and realized afterwards that the center hole was 5mm instead of 4mm which meant I would need to tap it for an M6 bolt. Rather than modifying Shift31's design in TinkerCad (still having trouble import