nprofile1qy2hwumn8ghj7un9d3shjtnyd968gmewwp6kyqpq7jpl9k4nrerqdvz3dda7n6s6ejnm5yjrj60ry9m2tua7kespjk6qrn5y0h (nprofile…5y0h) nprofile1qy2hwumn8ghj7un9d3shjtnyd968gmewwp6kyqpq4vmf45wf94h6tsqzu3znl20xtzw372ywcq9k2gvze299sljmddysrlecre (nprofile…ecre) flash carts are reasonaably cheap, i actually have a few of them myself, the everdrive X7 and pro can also live-usb link to your computer for debugging.
https://krikzz.com/our-products/cartridges/everdrive-64-pro.html
there's also summercart which is a much cheaper open-source one you can order a raw board of.
https://www.pcbway.com/project/shareproject/SC64_an_open_source_Nintendo_64_flashcart_14b9688a.html
Pretty much anyone playing N64 homebrew will be doing it on emulator but flash carts are so cheap and easy to get now anyone doing it on hardware probably already has one.