Asking for help. I’m trying to setup the softbank hikari and it keeps failing.

I just got my router today (tplink deco) and I’m trying to setup the softbank hikari. I followed the instructions and got to the step where I was able to connect to the dial up that I created “Download Site” thru ethernet. I don’t know what to do next. I have downloaded the easy setup tool and when I try to run the application it keeps failing or getting error, I’m not sure if that’s the next step I should be doing. Please help, I need this for work. Thank you.