Hello@Auhusto ,

Welcome to our community.

There are different passwords associated with the TP-Link DSL modem routers. If you've forgotten any of them, consider the following scenarios:
Scenario One: Forgot the login password to manage the modem router.
    1. Try the default login password on the router's bottom label, which is often "admin".
    2. Perform a hard reset on the router by pressing the reset button until all the lights flash briefly.
Scenario Two: Forgot the TP-Link ID password.
    1. Open the Tether app and select "Forget Password" on the login screen.
    2. Enter the email linked to your TP-Link ID and click "Reset Password," prompting a password reset email to be sent to you.
    3. Locate the email in your inbox, open it, and follow the steps to set a new password.
Scenario Three: Forgot the Wi-Fi password for the modem router.
    1. Check the bottom label of the router for the default Wi-Fi password, which is typically an 8-digit number.
    2. Open the Tether App, log into the router under Devices, and navigate to Tools > Wireless to view the Wi-Fi password.
    3. Connect your computer to the modem router via Ethernet, access tplinkmodem.net, and find the password under Advanced > Wireless > Wireless Settings.
    4. If all else fails, reset the modem router and use the default Wi-Fi password to reconnect. 
Note: A hard reset will revert the router to its factory settings without Internet access, requiring reconfiguration.