Infinite Lagrange's Steam "build" sucks when it comes to account linking and management. In-game there is no actual button to view/swap/bind accounts, necessitating you to do it all on your phone. This is really stupid, and I hope they simply... add the damn button.

In short: You should do this if you have existing mobile game data. If you are starting 100% new, ignore this.

The following steps should be done on mobile BEFORE opening on Steam:
1) Open the game, stay on the title screen.
2) Click the person icon in the top left. This opens the NetEase account management.
3) Click on the "Bind Account" button.
4) Select Steam.
5) Log in with your Steam details.
6) ???
7) Profit.

To ensure it is properly linked:
Go back to the "Bind Account" tab and check if Steam says "unbind" instead of "Bind." If it does, it should mean that its bound.

What's next?
Simply open the game for the first time on Steam and theoretically it will be using your proper account data.

You can unlink Steam and make the new account void.

1. Open the game on the regular PC/Mobile client.
2. Click the profile icon.
3. Login to the Steam account.
4. Go back to profile -> bind account.
5. Unbind Steam.
6. Log out and log back in to your regular account.

Now follow the guide above.