First of all, huge props for WebMeka (Mekarius) for his api data, and for his boss data and weapons data (which I ripped from webmeka)
Also thanks to Mega Man Maker for existing in the first place
Go to webmeka https://megamaker.webmeka.io/
At this site, on the left side, you either see your account name, or Login to Megaman Maker.
It it says Login to Megaman Maker, go ahead and login. You use the same username and password as you would for Mega Man Maker itself.
Once you have logged in, or if you were logged in already, click on My profile
Once there, you should see some text next to a slider toggle button saying: "Authorize the game to connect to the website to send data."
if the slider toggle button is gray, go ahead and click on it, it should turn blue.
Now you are done.
However, you still need your userid.
If you are logged into the exact same account in the mega man maker game, and not a linked account, you can copy the uid from the webmeka url
If not, you can eiter: