Hi, I am A. Stevens here to help with your question!
So most likely the issue is that after changing your router, your internet password ***** also changed.
I assume you are connecting to your printer wirelessly?
Or is it a wired connection?
So on your printer control panel display, you will want to navigate through the menu until you find the "network settings".
Then you will want to find your new network name, select "Connect", in which then it should prompt you for your new password.
Enter the password ***** then your printer should appear back online on your network.
Please let me know if this instruction does not work and we can try to run through it together.