Hello, this is Emily.
Did you recently change wifi connection and need to connect your printer to the new wifi? If so, this part needs to be done on the printer's local menu first, not via Windows. On your printer's LCD screen, find the settings menu and find the network related settings to connect to the new wifi. Since this is more of a Brother specific instruction, and every Brother's menu can be different, I won't be able to tell you the exact step by step. You need to refer to your printer's user guide to find that settings item.