Hello!
Method 1: Check on the router's nameplate.
Method 2: Check and modify on the router's web-based management page.
1. Connect your computer to the router's Wi-Fi network (or connect the computer to the router's LAN port using an Ethernet cable). Open your Internet browser. Enter 192.168.8.1 in your browser address bar and log in to your router's web-based management page.
2. Choose Wi-Fi Settings > Wi-Fi Basic Settings to check the current SSID and password. To modify the SSID and password, enter the new SSID and password and then click Save.

Thanks!