@satimis If you forgot your router wireless password, follow this guide to recover it. If you forgot your router web management password then follow this guide.

@Abhijit92 Double check your router bottom sticker to determine its FW region and HW version - details. What if you set your 5GHz band to channel 149 - does it stand after setting it ? Here's a...

@DmitriyF Here's how to configure a guest network on Omada controller. Most probably Method 2 and Method 3 are what you're looking for.

@fatih1 If you get the Tether app you can manage the router with this app, but nothing more, i.e. you won't get an SSH console access.

@fatih1 TP-Link home routers don't offer an SSH access. The TCP port 22 is open exclusively for the Tether app management - details.

@KYL88 You can try experimenting with the transmitting power of the AX72 to see if that helps in your case: