Should I do an online Master's degree or return to America to get a teaching license?

Hello! I'm currently an ALT and have been in Japan for about eight months. While I know that isn't long, I know I want to live in Japan for a fairly long time if not forever because teaching in the US just doesn't seem worth it, both from a financial perspective and a safety perspective. I know I'll be an ALT for a minimum of 2 more years as I'm on JET right now, but I'm having trouble deciding the best path forward to achieve my goals. I currently have a bachelor's degree, but I know most jobs here require a master's degree (if you want to get a job that isn't as an ALT or at an Eikaiwa). I would likely want to either teach at an international school or at a private school, and I potentially want to pursue a special license that would allow me to teach at a public school.

My Japanese isn't good enough to obtain a degree in Japan (at least not one taught in Japanese), so it seems like my options are to either get a Master's degree online while on JET or return to the US to get a teaching license and come back to Japan after three to five years of school plus teaching experience. I just don't know if it's better to stay in Japan (since getting back here can be fairly difficult, especially with the current pandemic) or to obtain a teaching license (which seems difficult to do online or I'd go for that option).