@Hassan-faiz.123 

There a few potential options you have.

Use another wireless device that allows 7-digit passwords to connect to the router and then change the wireless password.

Connect a device via Ethernet cable (usually computer) to the router and then change the wireless password.

In case you have enabled Remote Access on your router, then log into the router remotely and change the wireless password.

In case you have enabled the VPN Server of your router, then connect to the router via VPN connection and change the wireless password.

If none of the above is available to you, then you have to bite the bullet and restore your router to factory settings by pressing and holding the Reset button until you notice some response from the router's LEDs (usually you need press and hold the Reset button for at least 5 seconds). Then you can connect to the router's Wi-Fi via the SSID and password that are printed on the underside of the router.